root/chrome/browser/sync/profile_sync_service.cc

DEFINITIONS

1. ShouldShowActionOnUI
2. startup_controller_
3. IsSyncEnabledAndLoggedIn
4. IsOAuthRefreshTokenAvailable
5. Initialize
6. TrySyncDatatypePrefRecovery
7. StartSyncingWithServer
8. RegisterAuthNotifications
9. UnregisterAuthNotifications
10. RegisterDataTypeController
11. RegisterNonBlockingType
12. GetSessionModelAssociatorDeprecated
13. IsSessionsDataTypeControllerRunning
14. GetOpenTabsUIDelegate
15. GetFaviconCache
16. GetLocalDeviceInfo
17. GetDeviceInfo
18. GetAllSignedInDevices
19. GetLocalSyncCacheGUID
20. AddObserverForDeviceInfoChange
21. RemoveObserverForDeviceInfoChange
22. GetDataTypeControllerStates
23. InitSettings
24. GetCredentials
25. InitializeBackend
26. IsEncryptedDatatypeEnabled
27. OnSyncConfigureRetry
28. OnProtocolEvent
29. OnDataTypeRequestsSyncStartup
30. StartUpSlowBackendComponents
31. OnGetTokenSuccess
32. OnGetTokenFailure
33. OnRefreshTokenAvailable
34. OnRefreshTokenRevoked
35. OnRefreshTokensLoaded
36. Shutdown
37. ShutdownImpl
38. DisableForUser
39. HasSyncSetupCompleted
40. SetSyncSetupCompleted
41. UpdateLastSyncedTime
42. NotifyObservers
43. NotifySyncCycleCompleted
44. ClearStaleErrors
45. ClearUnrecoverableError
46. RegisterNewDataType
47. OnUnrecoverableError
48. OnUnrecoverableErrorImpl
49. DisableBrokenDatatype
50. OnBackendInitialized
51. OnSyncCycleCompleted
52. OnExperimentsChanged
53. UpdateAuthErrorState
54. ConnectionStatusToAuthError
55. OnConnectionStatusChange
56. StopSyncingPermanently
57. OnPassphraseRequired
58. OnPassphraseAccepted
59. OnEncryptedTypesChanged
60. OnEncryptionComplete
61. OnMigrationNeededForTypes
62. OnActionableError
63. OnConfigureDone
64. OnConfigureRetry
65. OnConfigureStart
66. QuerySyncStatusSummary
67. QuerySyncStatusSummaryString
68. GetBackendInitializationStateString
69. auto_start_enabled
70. setup_in_progress
71. QueryDetailedSyncStatus
72. GetAuthError
73. FirstSetupInProgress
74. SetSetupInProgress
75. sync_initialized
76. waiting_for_auth
77. current_experiments
78. HasUnrecoverableError
79. IsPassphraseRequired
80. IsPassphraseRequiredForDecryption
81. GetLastSyncedTimeString
82. UpdateSelectedTypesHistogram
83. RefreshSpareBootstrapToken
84. OnUserChoseDatatypes
85. ChangePreferredDataTypes
86. GetActiveDataTypes
87. GetPreferredDataTypes
88. GetPreferredDirectoryDataTypes
89. GetPreferredNonBlockingDataTypes
90. GetRegisteredDataTypes
91. GetRegisteredDirectoryDataTypes
92. GetRegisteredNonBlockingDataTypes
93. IsUsingSecondaryPassphrase
94. GetPassphraseType
95. GetExplicitPassphraseTime
96. IsCryptographerReady
97. ConfigurePriorityDataTypes
98. ConfigureDataTypeManager
99. GetUserShare
100. GetLastSessionSnapshot
101. HasUnsyncedItems
102. GetBackendMigratorForTest
103. GetModelSafeRoutingInfo
104. GetTypeStatusMap
105. ActivateDataType
106. DeactivateDataType
107. ConsumeCachedPassphraseIfPossible
108. RequestAccessToken
109. SetEncryptionPassphrase
110. SetDecryptionPassphrase
111. EnableEncryptEverything
112. encryption_pending
113. EncryptEverythingEnabled
114. GetEncryptedDataTypes
115. OnSyncManagedPrefChange
116. GoogleSigninSucceeded
117. GoogleSignedOut
118. AddObserver
119. RemoveObserver
120. AddProtocolEventObserver
121. RemoveProtocolEventObserver
122. HasObserver
123. GetJsController
124. SyncEvent
125. IsSyncEnabled
126. IsManaged
127. ShouldPushChanges
128. StopAndSuppress
129. IsStartSuppressed
130. signin
131. UnsuppressAndStart
132. AcknowledgeSyncedTypes
133. ReconfigureDatatypeManager
134. failed_data_types_handler
135. OnInternalUnrecoverableError
136. IsRetryingAccessTokenFetchForTest
137. GetAccessTokenForTest
138. GetJsEventHandler
139. GetSessionsSyncableService
140. last_get_token_error
141. GetSyncTokenStatus
142. OverrideNetworkResourcesForTest

// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "chrome/browser/sync/profile_sync_service.h"

#include <cstddef>
#include <map>
#include <set>
#include <utility>

#include "base/basictypes.h"
#include "base/bind.h"
#include "base/callback.h"
#include "base/command_line.h"
#include "base/compiler_specific.h"
#include "base/logging.h"
#include "base/memory/ref_counted.h"
#include "base/message_loop/message_loop.h"
#include "base/metrics/histogram.h"
#include "base/strings/string16.h"
#include "base/strings/stringprintf.h"
#include "base/threading/thread_restrictions.h"
#include "build/build_config.h"
#include "chrome/browser/bookmarks/enhanced_bookmarks_features.h"
#include "chrome/browser/browser_process.h"
#include "chrome/browser/chrome_notification_types.h"
#include "chrome/browser/defaults.h"
#include "chrome/browser/net/chrome_cookie_notification_details.h"
#include "chrome/browser/prefs/pref_service_syncable.h"
#include "chrome/browser/profiles/profile.h"
#include "chrome/browser/services/gcm/gcm_profile_service.h"
#include "chrome/browser/services/gcm/gcm_profile_service_factory.h"
#include "chrome/browser/signin/about_signin_internals_factory.h"
#include "chrome/browser/signin/profile_oauth2_token_service_factory.h"
#include "chrome/browser/signin/signin_manager_factory.h"
#include "chrome/browser/sync/backend_migrator.h"
#include "chrome/browser/sync/glue/change_processor.h"
#include "chrome/browser/sync/glue/chrome_report_unrecoverable_error.h"
#include "chrome/browser/sync/glue/device_info.h"
#include "chrome/browser/sync/glue/favicon_cache.h"
#include "chrome/browser/sync/glue/session_data_type_controller.h"
#include "chrome/browser/sync/glue/session_model_associator.h"
#include "chrome/browser/sync/glue/sync_backend_host.h"
#include "chrome/browser/sync/glue/sync_backend_host_impl.h"
#include "chrome/browser/sync/glue/sync_start_util.h"
#include "chrome/browser/sync/glue/synced_device_tracker.h"
#include "chrome/browser/sync/glue/typed_url_data_type_controller.h"
#include "chrome/browser/sync/managed_user_signin_manager_wrapper.h"
#include "chrome/browser/sync/profile_sync_components_factory_impl.h"
#include "chrome/browser/sync/sessions2/notification_service_sessions_router.h"
#include "chrome/browser/sync/sessions2/sessions_sync_manager.h"
#include "chrome/browser/sync/sync_error_controller.h"
#include "chrome/browser/ui/browser.h"
#include "chrome/browser/ui/browser_list.h"
#include "chrome/browser/ui/browser_window.h"
#include "chrome/browser/ui/global_error/global_error_service.h"
#include "chrome/browser/ui/global_error/global_error_service_factory.h"
#include "chrome/common/chrome_switches.h"
#include "chrome/common/chrome_version_info.h"
#include "chrome/common/pref_names.h"
#include "chrome/common/url_constants.h"
#include "components/signin/core/browser/about_signin_internals.h"
#include "components/signin/core/browser/profile_oauth2_token_service.h"
#include "components/signin/core/browser/signin_manager.h"
#include "components/sync_driver/data_type_controller.h"
#include "components/sync_driver/pref_names.h"
#include "components/sync_driver/system_encryptor.h"
#include "components/sync_driver/user_selectable_sync_type.h"
#include "components/user_prefs/pref_registry_syncable.h"
#include "content/public/browser/notification_details.h"
#include "content/public/browser/notification_service.h"
#include "content/public/browser/notification_source.h"
#include "google_apis/gaia/gaia_constants.h"
#include "grit/generated_resources.h"
#include "net/cookies/cookie_monster.h"
#include "net/url_request/url_request_context_getter.h"
#include "sync/api/sync_error.h"
#include "sync/internal_api/public/configure_reason.h"
#include "sync/internal_api/public/http_bridge_network_resources.h"
#include "sync/internal_api/public/network_resources.h"
#include "sync/internal_api/public/sync_core_proxy.h"
#include "sync/internal_api/public/sync_encryption_handler.h"
#include "sync/internal_api/public/util/experiments.h"
#include "sync/internal_api/public/util/sync_string_conversions.h"
#include "sync/js/js_arg_list.h"
#include "sync/js/js_event_details.h"
#include "sync/util/cryptographer.h"
#include "ui/base/l10n/l10n_util.h"
#include "ui/base/l10n/time_format.h"

#if defined(ENABLE_MANAGED_USERS)
#include "chrome/browser/managed_mode/managed_user_constants.h"
#endif

#if defined(OS_ANDROID)
#include "sync/internal_api/public/read_transaction.h"
#endif

using browser_sync::ChangeProcessor;
using browser_sync::DataTypeController;
using browser_sync::DataTypeManager;
using browser_sync::FailedDataTypesHandler;
using browser_sync::NotificationServiceSessionsRouter;
using browser_sync::ProfileSyncServiceStartBehavior;
using browser_sync::SyncBackendHost;
using syncer::ModelType;
using syncer::ModelTypeSet;
using syncer::JsBackend;
using syncer::JsController;
using syncer::JsEventDetails;
using syncer::JsEventHandler;
using syncer::ModelSafeRoutingInfo;
using syncer::SyncCredentials;
using syncer::SyncProtocolError;
using syncer::WeakHandle;

typedef GoogleServiceAuthError AuthError;

const char* ProfileSyncService::kSyncServerUrl =
    "https://clients4.google.com/chrome-sync";

const char* ProfileSyncService::kDevServerUrl =
    "https://clients4.google.com/chrome-sync/dev";

const char kSyncUnrecoverableErrorHistogram[] =
    "Sync.UnrecoverableErrors";

const net::BackoffEntry::Policy kRequestAccessTokenBackoffPolicy = {
  // Number of initial errors (in sequence) to ignore before applying
  // exponential back-off rules.
  0,

  // Initial delay for exponential back-off in ms.
  2000,

  // Factor by which the waiting time will be multiplied.
  2,

  // Fuzzing percentage. ex: 10% will spread requests randomly
  // between 90%-100% of the calculated time.
  0.2, // 20%

  // Maximum amount of time we are willing to delay our request in ms.
  // TODO(pavely): crbug.com/246686 ProfileSyncService should retry
  // RequestAccessToken on connection state change after backoff
  1000 * 3600 * 4, // 4 hours.

  // Time to keep an entry from being discarded even when it
  // has no significant state, -1 to never discard.
  -1,

  // Don't use initial delay unless the last request was an error.
  false,
};

bool ShouldShowActionOnUI(
    const syncer::SyncProtocolError& error) {
  return (error.action != syncer::UNKNOWN_ACTION &&
          error.action != syncer::DISABLE_SYNC_ON_CLIENT &&
          error.action != syncer::STOP_SYNC_FOR_DISABLED_ACCOUNT);
}

ProfileSyncService::ProfileSyncService(
    ProfileSyncComponentsFactory* factory,
    Profile* profile,
    ManagedUserSigninManagerWrapper* signin_wrapper,
    ProfileOAuth2TokenService* oauth2_token_service,
    ProfileSyncServiceStartBehavior start_behavior)
    : OAuth2TokenService::Consumer("sync"),
      last_auth_error_(AuthError::AuthErrorNone()),
      passphrase_required_reason_(syncer::REASON_PASSPHRASE_NOT_REQUIRED),
      factory_(factory),
      profile_(profile),
      sync_prefs_(profile_->GetPrefs()),
      sync_service_url_(kDevServerUrl),
      is_first_time_sync_configure_(false),
      backend_initialized_(false),
      sync_disabled_by_admin_(false),
      is_auth_in_progress_(false),
      signin_(signin_wrapper),
      unrecoverable_error_reason_(ERROR_REASON_UNSET),
      expect_sync_configuration_aborted_(false),
      encrypted_types_(syncer::SyncEncryptionHandler::SensitiveTypes()),
      encrypt_everything_(false),
      encryption_pending_(false),
      configure_status_(DataTypeManager::UNKNOWN),
      oauth2_token_service_(oauth2_token_service),
      request_access_token_backoff_(&kRequestAccessTokenBackoffPolicy),
      weak_factory_(this),
      startup_controller_weak_factory_(this),
      connection_status_(syncer::CONNECTION_NOT_ATTEMPTED),
      last_get_token_error_(GoogleServiceAuthError::AuthErrorNone()),
      network_resources_(new syncer::HttpBridgeNetworkResources),
      startup_controller_(
          start_behavior,
          oauth2_token_service,
          &sync_prefs_,
          signin_wrapper,
          base::Bind(&ProfileSyncService::StartUpSlowBackendComponents,
                     startup_controller_weak_factory_.GetWeakPtr())) {
  DCHECK(profile);
  // By default, dev, canary, and unbranded Chromium users will go to the
  // development servers. Development servers have more features than standard
  // sync servers. Users with officially-branded Chrome stable and beta builds
  // will go to the standard sync servers.
  //
  // GetChannel hits the registry on Windows. See http://crbug.com/70380.
  base::ThreadRestrictions::ScopedAllowIO allow_io;
  chrome::VersionInfo::Channel channel = chrome::VersionInfo::GetChannel();
  if (channel == chrome::VersionInfo::CHANNEL_STABLE ||
      channel == chrome::VersionInfo::CHANNEL_BETA) {
    sync_service_url_ = GURL(kSyncServerUrl);
  }

  if (!CommandLine::ForCurrentProcess()->HasSwitch(
      switches::kDisableSyncSessionsV2)) {
    syncer::SyncableService::StartSyncFlare flare(
        sync_start_util::GetFlareForSyncableService(profile->GetPath()));
    scoped_ptr<browser_sync::LocalSessionEventRouter> router(
        new NotificationServiceSessionsRouter(profile, flare));
    sessions_sync_manager_.reset(
        new SessionsSyncManager(profile, this, router.Pass()));
  }
}

ProfileSyncService::~ProfileSyncService() {
  sync_prefs_.RemoveSyncPrefObserver(this);
  // Shutdown() should have been called before destruction.
  CHECK(!backend_initialized_);
}

bool ProfileSyncService::IsSyncEnabledAndLoggedIn() {
  // Exit if sync is disabled.
  if (IsManaged() || sync_prefs_.IsStartSuppressed())
    return false;

  // Sync is logged in if there is a non-empty effective username.
  return !signin_->GetEffectiveUsername().empty();
}

bool ProfileSyncService::IsOAuthRefreshTokenAvailable() {
  if (!oauth2_token_service_)
    return false;

  return oauth2_token_service_->RefreshTokenIsAvailable(
      signin_->GetAccountIdToUse());
}

void ProfileSyncService::Initialize() {
  InitSettings();

  // We clear this here (vs Shutdown) because we want to remember that an error
  // happened on shutdown so we can display details (message, location) about it
  // in about:sync.
  ClearStaleErrors();

  sync_prefs_.AddSyncPrefObserver(this);

  // For now, the only thing we can do through policy is to turn sync off.
  if (IsManaged()) {
    DisableForUser();
    return;
  }

  RegisterAuthNotifications();

  if (!HasSyncSetupCompleted() || signin_->GetEffectiveUsername().empty()) {
    // Clean up in case of previous crash / setup abort / signout.
    DisableForUser();
  }

  TrySyncDatatypePrefRecovery();

  last_synced_time_ = sync_prefs_.GetLastSyncedTime();

#if defined(OS_CHROMEOS)
  std::string bootstrap_token = sync_prefs_.GetEncryptionBootstrapToken();
  if (bootstrap_token.empty()) {
    sync_prefs_.SetEncryptionBootstrapToken(
        sync_prefs_.GetSpareBootstrapToken());
  }
#endif

#if !defined(OS_ANDROID)
  DCHECK(sync_error_controller_ == NULL)
      << "Initialize() called more than once.";
  sync_error_controller_.reset(new SyncErrorController(this));
  AddObserver(sync_error_controller_.get());
#endif

  startup_controller_.Reset(GetRegisteredDataTypes());
  startup_controller_.TryStart();
}

void ProfileSyncService::TrySyncDatatypePrefRecovery() {
  DCHECK(!sync_initialized());
  if (!HasSyncSetupCompleted())
    return;

  // There was a bug where OnUserChoseDatatypes was not properly called on
  // configuration (see crbug.com/154940). We detect this by checking whether
  // kSyncKeepEverythingSynced has a default value. If so, and sync setup has
  // completed, it means sync was not properly configured, so we manually
  // set kSyncKeepEverythingSynced.
  PrefService* const pref_service = profile_->GetPrefs();
  if (!pref_service)
    return;
  if (GetPreferredDataTypes().Size() > 1)
    return;

  const PrefService::Preference* keep_everything_synced =
      pref_service->FindPreference(
          sync_driver::prefs::kSyncKeepEverythingSynced);
  // This will be false if the preference was properly set or if it's controlled
  // by policy.
  if (!keep_everything_synced->IsDefaultValue())
    return;

  // kSyncKeepEverythingSynced was not properly set. Set it and the preferred
  // types now, before we configure.
  UMA_HISTOGRAM_COUNTS("Sync.DatatypePrefRecovery", 1);
  sync_prefs_.SetKeepEverythingSynced(true);
  syncer::ModelTypeSet registered_types = GetRegisteredDataTypes();
  sync_prefs_.SetPreferredDataTypes(registered_types,
                                    registered_types);
}

void ProfileSyncService::StartSyncingWithServer() {
  if (backend_)
    backend_->StartSyncingWithServer();
}

void ProfileSyncService::RegisterAuthNotifications() {
  oauth2_token_service_->AddObserver(this);
  if (signin())
    signin()->AddObserver(this);
}

void ProfileSyncService::UnregisterAuthNotifications() {
  if (signin())
    signin()->RemoveObserver(this);
  oauth2_token_service_->RemoveObserver(this);
}

void ProfileSyncService::RegisterDataTypeController(
    DataTypeController* data_type_controller) {
  DCHECK_EQ(data_type_controllers_.count(data_type_controller->type()), 0U);
  DCHECK(!GetRegisteredNonBlockingDataTypes().Has(
      data_type_controller->type()));
  data_type_controllers_[data_type_controller->type()] =
      data_type_controller;
}

void ProfileSyncService::RegisterNonBlockingType(syncer::ModelType type) {
  DCHECK_EQ(data_type_controllers_.count(type), 0U);
  DCHECK(!GetRegisteredNonBlockingDataTypes().Has(type));
  non_blocking_types_.Put(type);
}

browser_sync::SessionModelAssociator*
    ProfileSyncService::GetSessionModelAssociatorDeprecated() {
  if (!IsSessionsDataTypeControllerRunning())
    return NULL;

  // If we're using sessions V2, there's no model associator.
  if (sessions_sync_manager_.get())
    return NULL;

  return static_cast<browser_sync::SessionDataTypeController*>(
      data_type_controllers_.find(
      syncer::SESSIONS)->second.get())->GetModelAssociator();
}

bool ProfileSyncService::IsSessionsDataTypeControllerRunning() const {
  return data_type_controllers_.find(syncer::SESSIONS) !=
      data_type_controllers_.end() &&
      data_type_controllers_.find(syncer::SESSIONS)->second->state() ==
      DataTypeController::RUNNING;
}

browser_sync::OpenTabsUIDelegate* ProfileSyncService::GetOpenTabsUIDelegate() {
  if (!IsSessionsDataTypeControllerRunning())
    return NULL;

  if (!CommandLine::ForCurrentProcess()->HasSwitch(
      switches::kDisableSyncSessionsV2)) {
    return sessions_sync_manager_.get();
  } else {
    return GetSessionModelAssociatorDeprecated();
  }
}

browser_sync::FaviconCache* ProfileSyncService::GetFaviconCache() {
  // TODO(tim): Clean this up (or remove) once there's only one implementation.
  // Bug 98892.
  if (!CommandLine::ForCurrentProcess()->HasSwitch(
      switches::kDisableSyncSessionsV2)) {
    return sessions_sync_manager_->GetFaviconCache();
  } else if (GetSessionModelAssociatorDeprecated()) {
    return GetSessionModelAssociatorDeprecated()->GetFaviconCache();
  } else {
    return NULL;
  }
}

scoped_ptr<browser_sync::DeviceInfo>
ProfileSyncService::GetLocalDeviceInfo() const {
  if (backend_) {
    browser_sync::SyncedDeviceTracker* device_tracker =
        backend_->GetSyncedDeviceTracker();
    if (device_tracker)
      return device_tracker->ReadLocalDeviceInfo();
  }
  return scoped_ptr<browser_sync::DeviceInfo>();
}

scoped_ptr<browser_sync::DeviceInfo>
ProfileSyncService::GetDeviceInfo(const std::string& client_id) const {
  if (backend_) {
    browser_sync::SyncedDeviceTracker* device_tracker =
        backend_->GetSyncedDeviceTracker();
    if (device_tracker)
      return device_tracker->ReadDeviceInfo(client_id);
  }
  return scoped_ptr<browser_sync::DeviceInfo>();
}

ScopedVector<browser_sync::DeviceInfo>
    ProfileSyncService::GetAllSignedInDevices() const {
  ScopedVector<browser_sync::DeviceInfo> devices;
  if (backend_) {
    browser_sync::SyncedDeviceTracker* device_tracker =
        backend_->GetSyncedDeviceTracker();
    if (device_tracker) {
      // TODO(lipalani) - Make device tracker return a scoped vector.
      device_tracker->GetAllSyncedDeviceInfo(&devices);
    }
  }
  return devices.Pass();
}

std::string ProfileSyncService::GetLocalSyncCacheGUID() const {
  if (backend_) {
    browser_sync::SyncedDeviceTracker* device_tracker =
        backend_->GetSyncedDeviceTracker();
    if (device_tracker) {
      return device_tracker->cache_guid();
    }
  }
  return std::string();
}

// Notifies the observer of any device info changes.
void ProfileSyncService::AddObserverForDeviceInfoChange(
    browser_sync::SyncedDeviceTracker::Observer* observer) {
  if (backend_) {
    browser_sync::SyncedDeviceTracker* device_tracker =
        backend_->GetSyncedDeviceTracker();
    if (device_tracker) {
      device_tracker->AddObserver(observer);
    }
  }
}

// Removes the observer from device info change notification.
void ProfileSyncService::RemoveObserverForDeviceInfoChange(
    browser_sync::SyncedDeviceTracker::Observer* observer) {
  if (backend_) {
    browser_sync::SyncedDeviceTracker* device_tracker =
        backend_->GetSyncedDeviceTracker();
    if (device_tracker) {
      device_tracker->RemoveObserver(observer);
    }
  }
}

void ProfileSyncService::GetDataTypeControllerStates(
  browser_sync::DataTypeController::StateMap* state_map) const {
    for (browser_sync::DataTypeController::TypeMap::const_iterator iter =
         data_type_controllers_.begin(); iter != data_type_controllers_.end();
         ++iter)
      (*state_map)[iter->first] = iter->second.get()->state();
}

void ProfileSyncService::InitSettings() {
  const CommandLine& command_line = *CommandLine::ForCurrentProcess();

  // Override the sync server URL from the command-line, if sync server
  // command-line argument exists.
  if (command_line.HasSwitch(switches::kSyncServiceURL)) {
    std::string value(command_line.GetSwitchValueASCII(
        switches::kSyncServiceURL));
    if (!value.empty()) {
      GURL custom_sync_url(value);
      if (custom_sync_url.is_valid()) {
        sync_service_url_ = custom_sync_url;
      } else {
        LOG(WARNING) << "The following sync URL specified at the command-line "
                     << "is invalid: " << value;
      }
    }
  }
}

SyncCredentials ProfileSyncService::GetCredentials() {
  SyncCredentials credentials;
  credentials.email = signin_->GetEffectiveUsername();
  DCHECK(!credentials.email.empty());
  credentials.sync_token = access_token_;

  if (credentials.sync_token.empty())
    credentials.sync_token = "credentials_lost";
  return credentials;
}

void ProfileSyncService::InitializeBackend(bool delete_stale_data) {
  if (!backend_) {
    NOTREACHED();
    return;
  }

  SyncCredentials credentials = GetCredentials();

  scoped_refptr<net::URLRequestContextGetter> request_context_getter(
      profile_->GetRequestContext());

  if (delete_stale_data)
    ClearStaleErrors();

  scoped_ptr<syncer::UnrecoverableErrorHandler>
      backend_unrecoverable_error_handler(
          new browser_sync::BackendUnrecoverableErrorHandler(
              MakeWeakHandle(weak_factory_.GetWeakPtr())));

  backend_->Initialize(
      this,
      sync_thread_.Pass(),
      GetJsEventHandler(),
      sync_service_url_,
      credentials,
      delete_stale_data,
      scoped_ptr<syncer::SyncManagerFactory>(
          new syncer::SyncManagerFactory).Pass(),
      backend_unrecoverable_error_handler.Pass(),
      &browser_sync::ChromeReportUnrecoverableError,
      network_resources_.get());
}

bool ProfileSyncService::IsEncryptedDatatypeEnabled() const {
  if (encryption_pending())
    return true;
  const syncer::ModelTypeSet preferred_types = GetPreferredDataTypes();
  const syncer::ModelTypeSet encrypted_types = GetEncryptedDataTypes();
  DCHECK(encrypted_types.Has(syncer::PASSWORDS));
  return !Intersection(preferred_types, encrypted_types).Empty();
}

void ProfileSyncService::OnSyncConfigureRetry() {
  // Note: in order to handle auth failures that arise before the backend is
  // initialized (e.g. from invalidation notifier, or downloading new control
  // types), we have to gracefully handle configuration retries at all times.
  // At this point an auth error badge should be shown, which once resolved
  // will trigger a new sync cycle.
  NotifyObservers();
}

void ProfileSyncService::OnProtocolEvent(
    const syncer::ProtocolEvent& event) {
  FOR_EACH_OBSERVER(browser_sync::ProtocolEventObserver,
                    protocol_event_observers_,
                    OnProtocolEvent(event));
}

void ProfileSyncService::OnDataTypeRequestsSyncStartup(
    syncer::ModelType type) {
  DCHECK(syncer::UserTypes().Has(type));
  if (backend_.get()) {
    DVLOG(1) << "A data type requested sync startup, but it looks like "
                "something else beat it to the punch.";
    return;
  }

  if (!GetPreferredDataTypes().Has(type)) {
    // We can get here as datatype SyncableServices are typically wired up
    // to the native datatype even if sync isn't enabled.
    DVLOG(1) << "Dropping sync startup request because type "
             << syncer::ModelTypeToString(type) << "not enabled.";
    return;
  }

  startup_controller_.OnDataTypeRequestsSyncStartup(type);
}

void ProfileSyncService::StartUpSlowBackendComponents() {
  // Don't start up multiple times.
  DCHECK(!backend_);

  DCHECK(IsSyncEnabledAndLoggedIn());

  DCHECK(!sync_disabled_by_admin_);
  backend_.reset(
      factory_->CreateSyncBackendHost(
          profile_->GetDebugName(),
          profile_,
          sync_prefs_.AsWeakPtr()));

  // Initialize the backend.  Every time we start up a new SyncBackendHost,
  // we'll want to start from a fresh SyncDB, so delete any old one that might
  // be there.
  InitializeBackend(!HasSyncSetupCompleted());
}

void ProfileSyncService::OnGetTokenSuccess(
    const OAuth2TokenService::Request* request,
    const std::string& access_token,
    const base::Time& expiration_time) {
  DCHECK_EQ(access_token_request_, request);
  access_token_request_.reset();
  access_token_ = access_token;
  token_receive_time_ = base::Time::Now();
  last_get_token_error_ = GoogleServiceAuthError::AuthErrorNone();

  if (sync_prefs_.SyncHasAuthError()) {
    sync_prefs_.SetSyncAuthError(false);
    UMA_HISTOGRAM_ENUMERATION("Sync.SyncAuthError",
                              AUTH_ERROR_FIXED,
                              AUTH_ERROR_LIMIT);
  }

  if (backend_)
    backend_->UpdateCredentials(GetCredentials());
  else
    startup_controller_.TryStart();
}

void ProfileSyncService::OnGetTokenFailure(
    const OAuth2TokenService::Request* request,
    const GoogleServiceAuthError& error) {
  DCHECK_EQ(access_token_request_, request);
  DCHECK_NE(error.state(), GoogleServiceAuthError::NONE);
  access_token_request_.reset();
  last_get_token_error_ = error;
  switch (error.state()) {
    case GoogleServiceAuthError::CONNECTION_FAILED:
    case GoogleServiceAuthError::SERVICE_UNAVAILABLE: {
      // Transient error. Retry after some time.
      request_access_token_backoff_.InformOfRequest(false);
      next_token_request_time_ = base::Time::Now() +
          request_access_token_backoff_.GetTimeUntilRelease();
      request_access_token_retry_timer_.Start(
            FROM_HERE,
            request_access_token_backoff_.GetTimeUntilRelease(),
            base::Bind(&ProfileSyncService::RequestAccessToken,
                        weak_factory_.GetWeakPtr()));
      NotifyObservers();
      break;
    }
    case GoogleServiceAuthError::SERVICE_ERROR:
    case GoogleServiceAuthError::INVALID_GAIA_CREDENTIALS: {
      if (!sync_prefs_.SyncHasAuthError()) {
        sync_prefs_.SetSyncAuthError(true);
        UMA_HISTOGRAM_ENUMERATION("Sync.SyncAuthError",
                                  AUTH_ERROR_ENCOUNTERED,
                                  AUTH_ERROR_LIMIT);
      }
      // Fallthrough.
    }
    default: {
      // Show error to user.
      UpdateAuthErrorState(error);
    }
  }
}

void ProfileSyncService::OnRefreshTokenAvailable(
    const std::string& account_id) {
  if (account_id == signin_->GetAccountIdToUse())
    OnRefreshTokensLoaded();
}

void ProfileSyncService::OnRefreshTokenRevoked(
    const std::string& account_id) {
  if (!IsOAuthRefreshTokenAvailable()) {
    access_token_.clear();
    // The additional check around IsOAuthRefreshTokenAvailable() above
    // prevents us sounding the alarm if we actually have a valid token but
    // a refresh attempt failed for any variety of reasons
    // (e.g. flaky network). It's possible the token we do have is also
    // invalid, but in that case we should already have (or can expect) an
    // auth error sent from the sync backend.
    UpdateAuthErrorState(
        GoogleServiceAuthError(GoogleServiceAuthError::REQUEST_CANCELED));
  }
}

void ProfileSyncService::OnRefreshTokensLoaded() {
  // This notification gets fired when OAuth2TokenService loads the tokens
  // from storage.
  // Initialize the backend if sync is enabled. If the sync token was
  // not loaded, GetCredentials() will generate invalid credentials to
  // cause the backend to generate an auth error (crbug.com/121755).
  if (backend_) {
    RequestAccessToken();
  } else {
    startup_controller_.TryStart();
  }
}

void ProfileSyncService::Shutdown() {
  UnregisterAuthNotifications();

  ShutdownImpl(browser_sync::SyncBackendHost::STOP);
  if (sync_error_controller_) {
    // Destroy the SyncErrorController when the service shuts down for good.
    RemoveObserver(sync_error_controller_.get());
    sync_error_controller_.reset();
  }

  if (sync_thread_)
    sync_thread_->Stop();
}

void ProfileSyncService::ShutdownImpl(
    browser_sync::SyncBackendHost::ShutdownOption option) {
  if (!backend_)
    return;

  // First, we spin down the backend to stop change processing as soon as
  // possible.
  base::Time shutdown_start_time = base::Time::Now();
  backend_->StopSyncingForShutdown();

  // Stop all data type controllers, if needed.  Note that until Stop
  // completes, it is possible in theory to have a ChangeProcessor apply a
  // change from a native model.  In that case, it will get applied to the sync
  // database (which doesn't get destroyed until we destroy the backend below)
  // as an unsynced change.  That will be persisted, and committed on restart.
  if (data_type_manager_) {
    if (data_type_manager_->state() != DataTypeManager::STOPPED) {
      // When aborting as part of shutdown, we should expect an aborted sync
      // configure result, else we'll dcheck when we try to read the sync error.
      expect_sync_configuration_aborted_ = true;
      data_type_manager_->Stop();
    }
    data_type_manager_.reset();
  }

  // Shutdown the migrator before the backend to ensure it doesn't pull a null
  // snapshot.
  migrator_.reset();
  sync_js_controller_.AttachJsBackend(WeakHandle<syncer::JsBackend>());

  // Move aside the backend so nobody else tries to use it while we are
  // shutting it down.
  scoped_ptr<SyncBackendHost> doomed_backend(backend_.release());
  if (doomed_backend) {
    sync_thread_ = doomed_backend->Shutdown(option);
    doomed_backend.reset();
  }
  base::TimeDelta shutdown_time = base::Time::Now() - shutdown_start_time;
  UMA_HISTOGRAM_TIMES("Sync.Shutdown.BackendDestroyedTime", shutdown_time);

  weak_factory_.InvalidateWeakPtrs();

  startup_controller_.Reset(GetRegisteredDataTypes());

  // Clear various flags.
  expect_sync_configuration_aborted_ = false;
  is_auth_in_progress_ = false;
  backend_initialized_ = false;
  cached_passphrase_.clear();
  access_token_.clear();
  encryption_pending_ = false;
  encrypt_everything_ = false;
  encrypted_types_ = syncer::SyncEncryptionHandler::SensitiveTypes();
  passphrase_required_reason_ = syncer::REASON_PASSPHRASE_NOT_REQUIRED;
  request_access_token_retry_timer_.Stop();
  // Revert to "no auth error".
  if (last_auth_error_.state() != GoogleServiceAuthError::NONE)
    UpdateAuthErrorState(GoogleServiceAuthError::AuthErrorNone());

  NotifyObservers();
}

void ProfileSyncService::DisableForUser() {
  // Clear prefs (including SyncSetupHasCompleted) before shutting down so
  // PSS clients don't think we're set up while we're shutting down.
  sync_prefs_.ClearPreferences();
  ClearUnrecoverableError();
  ShutdownImpl(browser_sync::SyncBackendHost::DISABLE_AND_CLAIM_THREAD);
}

bool ProfileSyncService::HasSyncSetupCompleted() const {
  return sync_prefs_.HasSyncSetupCompleted();
}

void ProfileSyncService::SetSyncSetupCompleted() {
  sync_prefs_.SetSyncSetupCompleted();
}

void ProfileSyncService::UpdateLastSyncedTime() {
  last_synced_time_ = base::Time::Now();
  sync_prefs_.SetLastSyncedTime(last_synced_time_);
}

void ProfileSyncService::NotifyObservers() {
  FOR_EACH_OBSERVER(ProfileSyncServiceBase::Observer, observers_,
                    OnStateChanged());
}

void ProfileSyncService::NotifySyncCycleCompleted() {
  FOR_EACH_OBSERVER(ProfileSyncServiceBase::Observer, observers_,
                    OnSyncCycleCompleted());
}

void ProfileSyncService::ClearStaleErrors() {
  ClearUnrecoverableError();
  last_actionable_error_ = SyncProtocolError();
  // Clear the data type errors as well.
  failed_data_types_handler_.Reset();
}

void ProfileSyncService::ClearUnrecoverableError() {
  unrecoverable_error_reason_ = ERROR_REASON_UNSET;
  unrecoverable_error_message_.clear();
  unrecoverable_error_location_ = tracked_objects::Location();
}

void ProfileSyncService::RegisterNewDataType(syncer::ModelType data_type) {
  if (data_type_controllers_.count(data_type) > 0)
    return;
  NOTREACHED();
}

// An invariant has been violated.  Transition to an error state where we try
// to do as little work as possible, to avoid further corruption or crashes.
void ProfileSyncService::OnUnrecoverableError(
    const tracked_objects::Location& from_here,
    const std::string& message) {
  // Unrecoverable errors that arrive via the syncer::UnrecoverableErrorHandler
  // interface are assumed to originate within the syncer.
  unrecoverable_error_reason_ = ERROR_REASON_SYNCER;
  OnUnrecoverableErrorImpl(from_here, message, true);
}

void ProfileSyncService::OnUnrecoverableErrorImpl(
    const tracked_objects::Location& from_here,
    const std::string& message,
    bool delete_sync_database) {
  DCHECK(HasUnrecoverableError());
  unrecoverable_error_message_ = message;
  unrecoverable_error_location_ = from_here;

  UMA_HISTOGRAM_ENUMERATION(kSyncUnrecoverableErrorHistogram,
                            unrecoverable_error_reason_,
                            ERROR_REASON_LIMIT);
  NotifyObservers();
  std::string location;
  from_here.Write(true, true, &location);
  LOG(ERROR)
      << "Unrecoverable error detected at " << location
      << " -- ProfileSyncService unusable: " << message;

  // Shut all data types down.
  base::MessageLoop::current()->PostTask(FROM_HERE,
      base::Bind(&ProfileSyncService::ShutdownImpl,
                 weak_factory_.GetWeakPtr(),
                 delete_sync_database ?
                     browser_sync::SyncBackendHost::DISABLE_AND_CLAIM_THREAD :
                     browser_sync::SyncBackendHost::STOP_AND_CLAIM_THREAD));
}

// TODO(zea): Move this logic into the DataTypeController/DataTypeManager.
void ProfileSyncService::DisableBrokenDatatype(
    syncer::ModelType type,
    const tracked_objects::Location& from_here,
    std::string message) {
  // First deactivate the type so that no further server changes are
  // passed onto the change processor.
  DeactivateDataType(type);

  syncer::SyncError error(from_here,
                          syncer::SyncError::DATATYPE_ERROR,
                          message,
                          type);

  std::map<syncer::ModelType, syncer::SyncError> errors;
  errors[type] = error;

  // Update this before posting a task. So if a configure happens before
  // the task that we are going to post, this type would still be disabled.
  failed_data_types_handler_.UpdateFailedDataTypes(errors);

  base::MessageLoop::current()->PostTask(FROM_HERE,
      base::Bind(&ProfileSyncService::ReconfigureDatatypeManager,
                 weak_factory_.GetWeakPtr()));
}

void ProfileSyncService::OnBackendInitialized(
    const syncer::WeakHandle<syncer::JsBackend>& js_backend,
    const syncer::WeakHandle<syncer::DataTypeDebugInfoListener>&
        debug_info_listener,
    bool success) {
  is_first_time_sync_configure_ = !HasSyncSetupCompleted();

  if (is_first_time_sync_configure_) {
    UMA_HISTOGRAM_BOOLEAN("Sync.BackendInitializeFirstTimeSuccess", success);
  } else {
    UMA_HISTOGRAM_BOOLEAN("Sync.BackendInitializeRestoreSuccess", success);
  }

  base::Time on_backend_initialized_time = base::Time::Now();
  base::TimeDelta delta = on_backend_initialized_time -
      startup_controller_.start_backend_time();
  if (is_first_time_sync_configure_) {
    UMA_HISTOGRAM_LONG_TIMES("Sync.BackendInitializeFirstTime", delta);
  } else {
    UMA_HISTOGRAM_LONG_TIMES("Sync.BackendInitializeRestoreTime", delta);
  }

  if (!success) {
    // Something went unexpectedly wrong.  Play it safe: stop syncing at once
    // and surface error UI to alert the user sync has stopped.
    // Keep the directory around for now so that on restart we will retry
    // again and potentially succeed in presence of transient file IO failures
    // or permissions issues, etc.
    //
    // TODO(rlarocque): Consider making this UnrecoverableError less special.
    // Unlike every other UnrecoverableError, it does not delete our sync data.
    // This exception made sense at the time it was implemented, but our new
    // directory corruption recovery mechanism makes it obsolete.  By the time
    // we get here, we will have already tried and failed to delete the
    // directory.  It would be no big deal if we tried to delete it again.
    OnInternalUnrecoverableError(FROM_HERE,
                                 "BackendInitialize failure",
                                 false,
                                 ERROR_REASON_BACKEND_INIT_FAILURE);
    return;
  }

  backend_initialized_ = true;

  sync_js_controller_.AttachJsBackend(js_backend);
  debug_info_listener_ = debug_info_listener;

  if (protocol_event_observers_.might_have_observers()) {
    backend_->RequestBufferedProtocolEventsAndEnableForwarding();
  }

  syncer::SyncCoreProxy sync_core_proxy_ = backend_->GetSyncCoreProxy();

  // If we have a cached passphrase use it to decrypt/encrypt data now that the
  // backend is initialized. We want to call this before notifying observers in
  // case this operation affects the "passphrase required" status.
  ConsumeCachedPassphraseIfPossible();

  // The very first time the backend initializes is effectively the first time
  // we can say we successfully "synced".  last_synced_time_ will only be null
  // in this case, because the pref wasn't restored on StartUp.
  if (last_synced_time_.is_null()) {
    UpdateLastSyncedTime();
  }

  if (startup_controller_.auto_start_enabled() && !FirstSetupInProgress()) {
    // Backend is initialized but we're not in sync setup, so this must be an
    // autostart - mark our sync setup as completed and we'll start syncing
    // below.
    SetSyncSetupCompleted();
  }

  // Check HasSyncSetupCompleted() before NotifyObservers() to avoid spurious
  // data type configuration because observer may flag setup as complete and
  // trigger data type configuration.
  if (HasSyncSetupCompleted()) {
    ConfigureDataTypeManager();
  } else {
    DCHECK(FirstSetupInProgress());
  }

  NotifyObservers();
}

void ProfileSyncService::OnSyncCycleCompleted() {
  UpdateLastSyncedTime();
  if (IsSessionsDataTypeControllerRunning()) {
    // Trigger garbage collection of old sessions now that we've downloaded
    // any new session data.
    if (sessions_sync_manager_) {
      // Sessions V2.
      base::MessageLoop::current()->PostTask(FROM_HERE, base::Bind(
          &browser_sync::SessionsSyncManager::DoGarbageCollection,
              base::AsWeakPtr(sessions_sync_manager_.get())));
    } else {
      base::MessageLoop::current()->PostTask(FROM_HERE, base::Bind(
          &browser_sync::SessionModelAssociator::DeleteStaleSessions,
              GetSessionModelAssociatorDeprecated()->AsWeakPtr()));
    }
  }
  DVLOG(2) << "Notifying observers sync cycle completed";
  NotifySyncCycleCompleted();
}

void ProfileSyncService::OnExperimentsChanged(
    const syncer::Experiments& experiments) {
  if (current_experiments_.Matches(experiments))
    return;

  current_experiments_ = experiments;

  // Handle preference-backed experiments first.
  if (experiments.gcm_channel_state != syncer::Experiments::UNSET) {
    profile()->GetPrefs()->SetBoolean(prefs::kGCMChannelEnabled,
                                      experiments.gcm_channel_state ==
                                          syncer::Experiments::ENABLED);
    gcm::GCMProfileService* gcm_profile_service =
        gcm::GCMProfileServiceFactory::GetForProfile(profile());
    if (gcm_profile_service) {
      if (experiments.gcm_channel_state == syncer::Experiments::SUPPRESSED)
        gcm_profile_service->Stop();
      else
        gcm_profile_service->Start();
    }
  } else {
    profile()->GetPrefs()->ClearPref(prefs::kGCMChannelEnabled);
  }

  profile()->GetPrefs()->SetBoolean(prefs::kInvalidationServiceUseGCMChannel,
                                    experiments.gcm_invalidations_enabled);

  int bookmarks_experiment_state_before = profile_->GetPrefs()->GetInteger(
      sync_driver::prefs::kEnhancedBookmarksExperimentEnabled);
  // kEnhancedBookmarksExperiment flag could have values "", "1" and "0".
  // "" and "1" means experiment is enabled.
  if ((CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
           switches::kEnhancedBookmarksExperiment) != "0")) {
    profile_->GetPrefs()->SetInteger(
        sync_driver::prefs::kEnhancedBookmarksExperimentEnabled,
        experiments.enhanced_bookmarks_enabled ? kBookmarksExperimentEnabled
                                               : kNoBookmarksExperiment);
    profile_->GetPrefs()->SetString(
        sync_driver::prefs::kEnhancedBookmarksExtensionId,
        experiments.enhanced_bookmarks_ext_id);
  } else {
    // User opt-out from chrome://flags
    if (experiments.enhanced_bookmarks_enabled) {
      profile_->GetPrefs()->SetInteger(
          sync_driver::prefs::kEnhancedBookmarksExperimentEnabled,
          kBookmarksExperimentEnabledUserOptOut);
      // Keep extension id up-to-date in case will opt-in later.
      profile_->GetPrefs()->SetString(
          sync_driver::prefs::kEnhancedBookmarksExtensionId,
          experiments.enhanced_bookmarks_ext_id);
    } else {
      profile_->GetPrefs()->ClearPref(
          sync_driver::prefs::kEnhancedBookmarksExperimentEnabled);
      profile_->GetPrefs()->ClearPref(
          sync_driver::prefs::kEnhancedBookmarksExtensionId);
    }
  }
  BookmarksExperimentState bookmarks_experiment_state =
      static_cast<BookmarksExperimentState>(profile_->GetPrefs()->GetInteger(
          sync_driver::prefs::kEnhancedBookmarksExperimentEnabled));
  // If bookmark experiment state was changed update about flags experiment.
  if (bookmarks_experiment_state_before != bookmarks_experiment_state) {
    UpdateBookmarksExperiment(g_browser_process->local_state(),
                              bookmarks_experiment_state);
  }

  // If this is a first time sync for a client, this will be called before
  // OnBackendInitialized() to ensure the new datatypes are available at sync
  // setup. As a result, the migrator won't exist yet. This is fine because for
  // first time sync cases we're only concerned with making the datatype
  // available.
  if (migrator_.get() &&
      migrator_->state() != browser_sync::BackendMigrator::IDLE) {
    DVLOG(1) << "Dropping OnExperimentsChanged due to migrator busy.";
    return;
  }

  const syncer::ModelTypeSet registered_types = GetRegisteredDataTypes();
  syncer::ModelTypeSet to_add;
  const syncer::ModelTypeSet to_register =
      Difference(to_add, registered_types);
  DVLOG(2) << "OnExperimentsChanged called with types: "
           << syncer::ModelTypeSetToString(to_add);
  DVLOG(2) << "Enabling types: " << syncer::ModelTypeSetToString(to_register);

  for (syncer::ModelTypeSet::Iterator it = to_register.First();
       it.Good(); it.Inc()) {
    // Received notice to enable experimental type. Check if the type is
    // registered, and if not register a new datatype controller.
    RegisterNewDataType(it.Get());
  }

  // Check if the user has "Keep Everything Synced" enabled. If so, we want
  // to turn on all experimental types if they're not already on. Otherwise we
  // leave them off.
  // Note: if any types are already registered, we don't turn them on. This
  // covers the case where we're already in the process of reconfiguring
  // to turn an experimental type on.
  if (sync_prefs_.HasKeepEverythingSynced()) {
    // Mark all data types as preferred.
    sync_prefs_.SetPreferredDataTypes(registered_types, registered_types);

    // Only automatically turn on types if we have already finished set up.
    // Otherwise, just leave the experimental types on by default.
    if (!to_register.Empty() && HasSyncSetupCompleted() && migrator_) {
      DVLOG(1) << "Dynamically enabling new datatypes: "
               << syncer::ModelTypeSetToString(to_register);
      OnMigrationNeededForTypes(to_register);
    }
  }
}

void ProfileSyncService::UpdateAuthErrorState(const AuthError& error) {
  is_auth_in_progress_ = false;
  last_auth_error_ = error;

  NotifyObservers();
}

namespace {

AuthError ConnectionStatusToAuthError(
    syncer::ConnectionStatus status) {
  switch (status) {
    case syncer::CONNECTION_OK:
      return AuthError::AuthErrorNone();
      break;
    case syncer::CONNECTION_AUTH_ERROR:
      return AuthError(AuthError::INVALID_GAIA_CREDENTIALS);
      break;
    case syncer::CONNECTION_SERVER_ERROR:
      return AuthError(AuthError::CONNECTION_FAILED);
      break;
    default:
      NOTREACHED();
      return AuthError(AuthError::CONNECTION_FAILED);
  }
}

}  // namespace

void ProfileSyncService::OnConnectionStatusChange(
    syncer::ConnectionStatus status) {
  connection_status_update_time_ = base::Time::Now();
  connection_status_ = status;
  if (status == syncer::CONNECTION_AUTH_ERROR) {
    // Sync server returned error indicating that access token is invalid. It
    // could be either expired or access is revoked. Let's request another
    // access token and if access is revoked then request for token will fail
    // with corresponding error. If access token is repeatedly reported
    // invalid, there may be some issues with server, e.g. authentication
    // state is inconsistent on sync and token server. In that case, we
    // backoff token requests exponentially to avoid hammering token server
    // too much and to avoid getting same token due to token server's caching
    // policy. |request_access_token_retry_timer_| is used to backoff request
    // triggered by both auth error and failure talking to GAIA server.
    // Therefore, we're likely to reach the backoff ceiling more quickly than
    // you would expect from looking at the BackoffPolicy if both types of
    // errors happen. We shouldn't receive two errors back-to-back without
    // attempting a token/sync request in between, thus crank up request delay
    // unnecessary. This is because we won't make a sync request if we hit an
    // error until GAIA succeeds at sending a new token, and we won't request
    // a new token unless sync reports a token failure. But to be safe, don't
    // schedule request if this happens.
    if (request_access_token_retry_timer_.IsRunning()) {
      NOTREACHED();
    } else if (request_access_token_backoff_.failure_count() == 0) {
      // First time request without delay. Currently invalid token is used
      // to initialize sync backend and we'll always end up here. We don't
      // want to delay initialization.
      request_access_token_backoff_.InformOfRequest(false);
      RequestAccessToken();
    } else  {
      request_access_token_backoff_.InformOfRequest(false);
      request_access_token_retry_timer_.Start(
          FROM_HERE,
          request_access_token_backoff_.GetTimeUntilRelease(),
          base::Bind(&ProfileSyncService::RequestAccessToken,
                     weak_factory_.GetWeakPtr()));
    }
  } else {
    // Reset backoff time after successful connection.
    if (status == syncer::CONNECTION_OK) {
      // Request shouldn't be scheduled at this time. But if it is, it's
      // possible that sync flips between OK and auth error states rapidly,
      // thus hammers token server. To be safe, only reset backoff delay when
      // no scheduled request.
      if (request_access_token_retry_timer_.IsRunning()) {
        NOTREACHED();
      } else {
        request_access_token_backoff_.Reset();
      }
    }

    const GoogleServiceAuthError auth_error =
        ConnectionStatusToAuthError(status);
    DVLOG(1) << "Connection status change: " << auth_error.ToString();
    UpdateAuthErrorState(auth_error);
  }
}

void ProfileSyncService::StopSyncingPermanently() {
  sync_prefs_.SetStartSuppressed(true);
  DisableForUser();
}

void ProfileSyncService::OnPassphraseRequired(
    syncer::PassphraseRequiredReason reason,
    const sync_pb::EncryptedData& pending_keys) {
  DCHECK(backend_.get());
  DCHECK(backend_->IsNigoriEnabled());

  // TODO(lipalani) : add this check to other locations as well.
  if (HasUnrecoverableError()) {
    // When unrecoverable error is detected we post a task to shutdown the
    // backend. The task might not have executed yet.
    return;
  }

  DVLOG(1) << "Passphrase required with reason: "
           << syncer::PassphraseRequiredReasonToString(reason);
  passphrase_required_reason_ = reason;

  const syncer::ModelTypeSet types = GetPreferredDirectoryDataTypes();
  if (data_type_manager_) {
    // Reconfigure without the encrypted types (excluded implicitly via the
    // failed datatypes handler).
    data_type_manager_->Configure(types,
                                  syncer::CONFIGURE_REASON_CRYPTO);
  }

  // TODO(rlarocque): Support non-blocking types.  http://crbug.com/351005.

  // Notify observers that the passphrase status may have changed.
  NotifyObservers();
}

void ProfileSyncService::OnPassphraseAccepted() {
  DVLOG(1) << "Received OnPassphraseAccepted.";

  // If the pending keys were resolved via keystore, it's possible we never
  // consumed our cached passphrase. Clear it now.
  if (!cached_passphrase_.empty())
    cached_passphrase_.clear();

  // Reset passphrase_required_reason_ since we know we no longer require the
  // passphrase. We do this here rather than down in ResolvePassphraseRequired()
  // because that can be called by OnPassphraseRequired() if no encrypted data
  // types are enabled, and we don't want to clobber the true passphrase error.
  passphrase_required_reason_ = syncer::REASON_PASSPHRASE_NOT_REQUIRED;

  // Make sure the data types that depend on the passphrase are started at
  // this time.
  const syncer::ModelTypeSet types = GetPreferredDirectoryDataTypes();
  if (data_type_manager_) {
    // Re-enable any encrypted types if necessary.
    data_type_manager_->Configure(types,
                                  syncer::CONFIGURE_REASON_CRYPTO);
  }

  // TODO(rlarocque): Support non-blocking types.  http://crbug.com/351005.

  NotifyObservers();
}

void ProfileSyncService::OnEncryptedTypesChanged(
    syncer::ModelTypeSet encrypted_types,
    bool encrypt_everything) {
  encrypted_types_ = encrypted_types;
  encrypt_everything_ = encrypt_everything;
  DVLOG(1) << "Encrypted types changed to "
           << syncer::ModelTypeSetToString(encrypted_types_)
           << " (encrypt everything is set to "
           << (encrypt_everything_ ? "true" : "false") << ")";
  DCHECK(encrypted_types_.Has(syncer::PASSWORDS));

  // If sessions are encrypted, full history sync is not possible, and
  // delete directives are unnecessary.
  if (GetActiveDataTypes().Has(syncer::HISTORY_DELETE_DIRECTIVES) &&
      encrypted_types_.Has(syncer::SESSIONS)) {
    DisableBrokenDatatype(syncer::HISTORY_DELETE_DIRECTIVES,
                          FROM_HERE,
                          "Delete directives not supported with encryption.");
  }
}

void ProfileSyncService::OnEncryptionComplete() {
  DVLOG(1) << "Encryption complete";
  if (encryption_pending_ && encrypt_everything_) {
    encryption_pending_ = false;
    // This is to nudge the integration tests when encryption is
    // finished.
    NotifyObservers();
  }
}

void ProfileSyncService::OnMigrationNeededForTypes(
    syncer::ModelTypeSet types) {
  DCHECK(backend_initialized_);
  DCHECK(data_type_manager_.get());

  // Migrator must be valid, because we don't sync until it is created and this
  // callback originates from a sync cycle.
  migrator_->MigrateTypes(types);
}

void ProfileSyncService::OnActionableError(const SyncProtocolError& error) {
  last_actionable_error_ = error;
  DCHECK_NE(last_actionable_error_.action,
            syncer::UNKNOWN_ACTION);
  switch (error.action) {
    case syncer::UPGRADE_CLIENT:
    case syncer::CLEAR_USER_DATA_AND_RESYNC:
    case syncer::ENABLE_SYNC_ON_ACCOUNT:
    case syncer::STOP_AND_RESTART_SYNC:
      // TODO(lipalani) : if setup in progress we want to display these
      // actions in the popup. The current experience might not be optimal for
      // the user. We just dismiss the dialog.
      if (startup_controller_.setup_in_progress()) {
        StopSyncingPermanently();
        expect_sync_configuration_aborted_ = true;
      }
      // Trigger an unrecoverable error to stop syncing.
      OnInternalUnrecoverableError(FROM_HERE,
                                   last_actionable_error_.error_description,
                                   true,
                                   ERROR_REASON_ACTIONABLE_ERROR);
      break;
    case syncer::DISABLE_SYNC_ON_CLIENT:
      StopSyncingPermanently();
#if !defined(OS_CHROMEOS)
      // On desktop Chrome, sign out the user after a dashboard clear.
      // Skip sign out on ChromeOS/Android.
      if (!startup_controller_.auto_start_enabled())
        SigninManagerFactory::GetForProfile(profile_)->SignOut();
#endif
      break;
    case syncer::STOP_SYNC_FOR_DISABLED_ACCOUNT:
      // Sync disabled by domain admin. we should stop syncing until next
      // restart.
      sync_disabled_by_admin_ = true;
      ShutdownImpl(browser_sync::SyncBackendHost::DISABLE_AND_CLAIM_THREAD);
      break;
    default:
      NOTREACHED();
  }
  NotifyObservers();
}

void ProfileSyncService::OnConfigureDone(
    const browser_sync::DataTypeManager::ConfigureResult& result) {
  // We should have cleared our cached passphrase before we get here (in
  // OnBackendInitialized()).
  DCHECK(cached_passphrase_.empty());

  if (!sync_configure_start_time_.is_null()) {
    if (result.status == DataTypeManager::OK ||
        result.status == DataTypeManager::PARTIAL_SUCCESS) {
      base::Time sync_configure_stop_time = base::Time::Now();
      base::TimeDelta delta = sync_configure_stop_time -
          sync_configure_start_time_;
      if (is_first_time_sync_configure_) {
        UMA_HISTOGRAM_LONG_TIMES("Sync.ServiceInitialConfigureTime", delta);
      } else {
        UMA_HISTOGRAM_LONG_TIMES("Sync.ServiceSubsequentConfigureTime",
                                  delta);
      }
    }
    sync_configure_start_time_ = base::Time();
  }

  // Notify listeners that configuration is done.
  content::NotificationService::current()->Notify(
      chrome::NOTIFICATION_SYNC_CONFIGURE_DONE,
      content::Source<ProfileSyncService>(this),
      content::NotificationService::NoDetails());

  configure_status_ = result.status;
  DVLOG(1) << "PSS OnConfigureDone called with status: " << configure_status_;
  // The possible status values:
  //    ABORT - Configuration was aborted. This is not an error, if
  //            initiated by user.
  //    OK - Everything succeeded.
  //    PARTIAL_SUCCESS - Some datatypes failed to start.
  //    Everything else is an UnrecoverableError. So treat it as such.

  // First handle the abort case.
  if (configure_status_ == DataTypeManager::ABORTED &&
      expect_sync_configuration_aborted_) {
    DVLOG(0) << "ProfileSyncService::Observe Sync Configure aborted";
    expect_sync_configuration_aborted_ = false;
    return;
  }

  // Handle unrecoverable error.
  if (configure_status_ != DataTypeManager::OK &&
      configure_status_ != DataTypeManager::PARTIAL_SUCCESS) {
    // Something catastrophic had happened. We should only have one
    // error representing it.
    DCHECK_EQ(result.failed_data_types.size(),
              static_cast<unsigned int>(1));
    syncer::SyncError error = result.failed_data_types.begin()->second;
    DCHECK(error.IsSet());
    std::string message =
        "Sync configuration failed with status " +
        DataTypeManager::ConfigureStatusToString(configure_status_) +
        " during " + syncer::ModelTypeToString(error.model_type()) +
        ": " + error.message();
    LOG(ERROR) << "ProfileSyncService error: " << message;
    OnInternalUnrecoverableError(error.location(),
                                 message,
                                 true,
                                 ERROR_REASON_CONFIGURATION_FAILURE);
    return;
  }

  // We should never get in a state where we have no encrypted datatypes
  // enabled, and yet we still think we require a passphrase for decryption.
  DCHECK(!(IsPassphraseRequiredForDecryption() &&
           !IsEncryptedDatatypeEnabled()));

  // This must be done before we start syncing with the server to avoid
  // sending unencrypted data up on a first time sync.
  if (encryption_pending_)
    backend_->EnableEncryptEverything();
  NotifyObservers();

  if (migrator_.get() &&
      migrator_->state() != browser_sync::BackendMigrator::IDLE) {
    // Migration in progress.  Let the migrator know we just finished
    // configuring something.  It will be up to the migrator to call
    // StartSyncingWithServer() if migration is now finished.
    migrator_->OnConfigureDone(result);
  } else {
    StartSyncingWithServer();
  }
}

void ProfileSyncService::OnConfigureRetry() {
  // We should have cleared our cached passphrase before we get here (in
  // OnBackendInitialized()).
  DCHECK(cached_passphrase_.empty());

  OnSyncConfigureRetry();
}

void ProfileSyncService::OnConfigureStart() {
  sync_configure_start_time_ = base::Time::Now();
  NotifyObservers();
}

ProfileSyncService::SyncStatusSummary
      ProfileSyncService::QuerySyncStatusSummary() {
  if (HasUnrecoverableError()) {
    return UNRECOVERABLE_ERROR;
  } else if (!backend_) {
    return NOT_ENABLED;
  } else if (backend_.get() && !HasSyncSetupCompleted()) {
    return SETUP_INCOMPLETE;
  } else if (backend_.get() && HasSyncSetupCompleted() &&
             data_type_manager_.get() &&
             data_type_manager_->state() != DataTypeManager::CONFIGURED) {
    return DATATYPES_NOT_INITIALIZED;
  } else if (ShouldPushChanges()) {
    return INITIALIZED;
  }
  return UNKNOWN_ERROR;
}

std::string ProfileSyncService::QuerySyncStatusSummaryString() {
  SyncStatusSummary status = QuerySyncStatusSummary();
  switch (status) {
    case UNRECOVERABLE_ERROR:
      return "Unrecoverable error detected";
    case NOT_ENABLED:
      return "Syncing not enabled";
    case SETUP_INCOMPLETE:
      return "First time sync setup incomplete";
    case DATATYPES_NOT_INITIALIZED:
      return "Datatypes not fully initialized";
    case INITIALIZED:
      return "Sync service initialized";
    default:
      return "Status unknown: Internal error?";
  }
}

std::string ProfileSyncService::GetBackendInitializationStateString() const {
  return startup_controller_.GetBackendInitializationStateString();
}

bool ProfileSyncService::auto_start_enabled() const {
  return startup_controller_.auto_start_enabled();
}

bool ProfileSyncService::setup_in_progress() const {
  return startup_controller_.setup_in_progress();
}

bool ProfileSyncService::QueryDetailedSyncStatus(
    SyncBackendHost::Status* result) {
  if (backend_.get() && backend_initialized_) {
    *result = backend_->GetDetailedStatus();
    return true;
  } else {
    SyncBackendHost::Status status;
    status.sync_protocol_error = last_actionable_error_;
    *result = status;
    return false;
  }
}

const AuthError& ProfileSyncService::GetAuthError() const {
  return last_auth_error_;
}

bool ProfileSyncService::FirstSetupInProgress() const {
  return !HasSyncSetupCompleted() && startup_controller_.setup_in_progress();
}

void ProfileSyncService::SetSetupInProgress(bool setup_in_progress) {
  // This method is a no-op if |setup_in_progress_| remains unchanged.
  if (startup_controller_.setup_in_progress() == setup_in_progress)
    return;

  startup_controller_.set_setup_in_progress(setup_in_progress);
  if (!setup_in_progress && sync_initialized())
    ReconfigureDatatypeManager();
  NotifyObservers();
}

bool ProfileSyncService::sync_initialized() const {
  return backend_initialized_;
}

bool ProfileSyncService::waiting_for_auth() const {
  return is_auth_in_progress_;
}

const syncer::Experiments& ProfileSyncService::current_experiments() const {
  return current_experiments_;
}

bool ProfileSyncService::HasUnrecoverableError() const {
  return unrecoverable_error_reason_ != ERROR_REASON_UNSET;
}

bool ProfileSyncService::IsPassphraseRequired() const {
  return passphrase_required_reason_ !=
      syncer::REASON_PASSPHRASE_NOT_REQUIRED;
}

bool ProfileSyncService::IsPassphraseRequiredForDecryption() const {
  // If there is an encrypted datatype enabled and we don't have the proper
  // passphrase, we must prompt the user for a passphrase. The only way for the
  // user to avoid entering their passphrase is to disable the encrypted types.
  return IsEncryptedDatatypeEnabled() && IsPassphraseRequired();
}

base::string16 ProfileSyncService::GetLastSyncedTimeString() const {
  if (last_synced_time_.is_null())
    return l10n_util::GetStringUTF16(IDS_SYNC_TIME_NEVER);

  base::TimeDelta last_synced = base::Time::Now() - last_synced_time_;

  if (last_synced < base::TimeDelta::FromMinutes(1))
    return l10n_util::GetStringUTF16(IDS_SYNC_TIME_JUST_NOW);

  return ui::TimeFormat::Simple(ui::TimeFormat::FORMAT_ELAPSED,
                                ui::TimeFormat::LENGTH_SHORT, last_synced);
}

void ProfileSyncService::UpdateSelectedTypesHistogram(
    bool sync_everything, const syncer::ModelTypeSet chosen_types) const {
  if (!HasSyncSetupCompleted() ||
      sync_everything != sync_prefs_.HasKeepEverythingSynced()) {
    UMA_HISTOGRAM_BOOLEAN("Sync.SyncEverything", sync_everything);
  }

  // Only log the data types that are shown in the sync settings ui.
  // Note: the order of these types must match the ordering of
  // the respective types in ModelType
const browser_sync::user_selectable_type::UserSelectableSyncType
      user_selectable_types[] = {
    browser_sync::user_selectable_type::BOOKMARKS,
    browser_sync::user_selectable_type::PREFERENCES,
    browser_sync::user_selectable_type::PASSWORDS,
    browser_sync::user_selectable_type::AUTOFILL,
    browser_sync::user_selectable_type::THEMES,
    browser_sync::user_selectable_type::TYPED_URLS,
    browser_sync::user_selectable_type::EXTENSIONS,
    browser_sync::user_selectable_type::APPS,
    browser_sync::user_selectable_type::PROXY_TABS
  };

  COMPILE_ASSERT(32 == syncer::MODEL_TYPE_COUNT, UpdateCustomConfigHistogram);

  if (!sync_everything) {
    const syncer::ModelTypeSet current_types = GetPreferredDataTypes();

    syncer::ModelTypeSet type_set = syncer::UserSelectableTypes();
    syncer::ModelTypeSet::Iterator it = type_set.First();

    DCHECK_EQ(arraysize(user_selectable_types), type_set.Size());

    for (size_t i = 0; i < arraysize(user_selectable_types) && it.Good();
         ++i, it.Inc()) {
      const syncer::ModelType type = it.Get();
      if (chosen_types.Has(type) &&
          (!HasSyncSetupCompleted() || !current_types.Has(type))) {
        // Selected type has changed - log it.
        UMA_HISTOGRAM_ENUMERATION(
            "Sync.CustomSync",
            user_selectable_types[i],
            browser_sync::user_selectable_type::SELECTABLE_DATATYPE_COUNT + 1);
      }
    }
  }
}

#if defined(OS_CHROMEOS)
void ProfileSyncService::RefreshSpareBootstrapToken(
    const std::string& passphrase) {
  browser_sync::SystemEncryptor encryptor;
  syncer::Cryptographer temp_cryptographer(&encryptor);
  // The first 2 params (hostname and username) doesn't have any effect here.
  syncer::KeyParams key_params = {"localhost", "dummy", passphrase};

  std::string bootstrap_token;
  if (!temp_cryptographer.AddKey(key_params)) {
    NOTREACHED() << "Failed to add key to cryptographer.";
  }
  temp_cryptographer.GetBootstrapToken(&bootstrap_token);
  sync_prefs_.SetSpareBootstrapToken(bootstrap_token);
}
#endif

void ProfileSyncService::OnUserChoseDatatypes(
    bool sync_everything,
    syncer::ModelTypeSet chosen_types) {
  if (!backend_.get() && !HasUnrecoverableError()) {
    NOTREACHED();
    return;
  }

  UpdateSelectedTypesHistogram(sync_everything, chosen_types);
  sync_prefs_.SetKeepEverythingSynced(sync_everything);

  failed_data_types_handler_.Reset();
  if (GetActiveDataTypes().Has(syncer::HISTORY_DELETE_DIRECTIVES) &&
      encrypted_types_.Has(syncer::SESSIONS)) {
    DisableBrokenDatatype(syncer::HISTORY_DELETE_DIRECTIVES,
                          FROM_HERE,
                          "Delete directives not supported with encryption.");
  }
  ChangePreferredDataTypes(chosen_types);
  AcknowledgeSyncedTypes();
  NotifyObservers();
}

void ProfileSyncService::ChangePreferredDataTypes(
    syncer::ModelTypeSet preferred_types) {

  DVLOG(1) << "ChangePreferredDataTypes invoked";
  const syncer::ModelTypeSet registered_types = GetRegisteredDataTypes();
  const syncer::ModelTypeSet registered_preferred_types =
      Intersection(registered_types, preferred_types);
  sync_prefs_.SetPreferredDataTypes(registered_types,
                                    registered_preferred_types);

  // Now reconfigure the DTM.
  ReconfigureDatatypeManager();
}

syncer::ModelTypeSet ProfileSyncService::GetActiveDataTypes() const {
  const syncer::ModelTypeSet preferred_types = GetPreferredDataTypes();
  const syncer::ModelTypeSet failed_types =
      failed_data_types_handler_.GetFailedTypes();
  return Difference(preferred_types, failed_types);
}

syncer::ModelTypeSet ProfileSyncService::GetPreferredDataTypes() const {
  const syncer::ModelTypeSet registered_types = GetRegisteredDataTypes();
  const syncer::ModelTypeSet preferred_types =
      sync_prefs_.GetPreferredDataTypes(registered_types);
  return preferred_types;
}

syncer::ModelTypeSet
ProfileSyncService::GetPreferredDirectoryDataTypes() const {
  const syncer::ModelTypeSet registered_directory_types =
      GetRegisteredDirectoryDataTypes();
  const syncer::ModelTypeSet preferred_types =
      sync_prefs_.GetPreferredDataTypes(registered_directory_types);
  return preferred_types;
}

syncer::ModelTypeSet
ProfileSyncService::GetPreferredNonBlockingDataTypes() const {
  return sync_prefs_.GetPreferredDataTypes(GetRegisteredNonBlockingDataTypes());
}

syncer::ModelTypeSet ProfileSyncService::GetRegisteredDataTypes() const {
  return Union(GetRegisteredDirectoryDataTypes(),
               GetRegisteredNonBlockingDataTypes());
}

syncer::ModelTypeSet
ProfileSyncService::GetRegisteredDirectoryDataTypes() const {
  syncer::ModelTypeSet registered_types;
  // The data_type_controllers_ are determined by command-line flags; that's
  // effectively what controls the values returned here.
  for (DataTypeController::TypeMap::const_iterator it =
       data_type_controllers_.begin();
       it != data_type_controllers_.end(); ++it) {
    registered_types.Put(it->first);
  }
  return registered_types;
}

syncer::ModelTypeSet
ProfileSyncService::GetRegisteredNonBlockingDataTypes() const {
  return non_blocking_types_;
}

bool ProfileSyncService::IsUsingSecondaryPassphrase() const {
  syncer::PassphraseType passphrase_type = GetPassphraseType();
  return passphrase_type == syncer::FROZEN_IMPLICIT_PASSPHRASE ||
         passphrase_type == syncer::CUSTOM_PASSPHRASE;
}

syncer::PassphraseType ProfileSyncService::GetPassphraseType() const {
  return backend_->GetPassphraseType();
}

base::Time ProfileSyncService::GetExplicitPassphraseTime() const {
  return backend_->GetExplicitPassphraseTime();
}

bool ProfileSyncService::IsCryptographerReady(
    const syncer::BaseTransaction* trans) const {
  return backend_.get() && backend_->IsCryptographerReady(trans);
}

void ProfileSyncService::ConfigurePriorityDataTypes() {
  const syncer::ModelTypeSet priority_types =
      Intersection(GetPreferredDirectoryDataTypes(),
                   syncer::PriorityUserTypes());
  if (!priority_types.Empty()) {
    const syncer::ConfigureReason reason = HasSyncSetupCompleted() ?
        syncer::CONFIGURE_REASON_RECONFIGURATION :
        syncer::CONFIGURE_REASON_NEW_CLIENT;
    data_type_manager_->Configure(priority_types, reason);
  }
}

void ProfileSyncService::ConfigureDataTypeManager() {
  // Don't configure datatypes if the setup UI is still on the screen - this
  // is to help multi-screen setting UIs (like iOS) where they don't want to
  // start syncing data until the user is done configuring encryption options,
  // etc. ReconfigureDatatypeManager() will get called again once the UI calls
  // SetSetupInProgress(false).
  if (startup_controller_.setup_in_progress())
    return;

  bool restart = false;
  if (!data_type_manager_) {
    restart = true;
    data_type_manager_.reset(
        factory_->CreateDataTypeManager(debug_info_listener_,
                                        &data_type_controllers_,
                                        this,
                                        backend_.get(),
                                        this,
                                        &failed_data_types_handler_));

    // We create the migrator at the same time.
    migrator_.reset(
        new browser_sync::BackendMigrator(
            profile_->GetDebugName(), GetUserShare(),
            this, data_type_manager_.get(),
            base::Bind(&ProfileSyncService::StartSyncingWithServer,
                       base::Unretained(this))));
  }

  const syncer::ModelTypeSet types = GetPreferredDirectoryDataTypes();
  syncer::ConfigureReason reason = syncer::CONFIGURE_REASON_UNKNOWN;
  if (!HasSyncSetupCompleted()) {
    reason = syncer::CONFIGURE_REASON_NEW_CLIENT;
  } else if (restart) {
    // Datatype downloads on restart are generally due to newly supported
    // datatypes (although it's also possible we're picking up where a failed
    // previous configuration left off).
    // TODO(sync): consider detecting configuration recovery and setting
    // the reason here appropriately.
    reason = syncer::CONFIGURE_REASON_NEWLY_ENABLED_DATA_TYPE;
  } else {
    // The user initiated a reconfiguration (either to add or remove types).
    reason = syncer::CONFIGURE_REASON_RECONFIGURATION;
  }

  data_type_manager_->Configure(types, reason);
}

syncer::UserShare* ProfileSyncService::GetUserShare() const {
  if (backend_.get() && backend_initialized_) {
    return backend_->GetUserShare();
  }
  NOTREACHED();
  return NULL;
}

syncer::sessions::SyncSessionSnapshot
    ProfileSyncService::GetLastSessionSnapshot() const {
  if (backend_.get() && backend_initialized_) {
    return backend_->GetLastSessionSnapshot();
  }
  NOTREACHED();
  return syncer::sessions::SyncSessionSnapshot();
}

bool ProfileSyncService::HasUnsyncedItems() const {
  if (backend_.get() && backend_initialized_) {
    return backend_->HasUnsyncedItems();
  }
  NOTREACHED();
  return false;
}

browser_sync::BackendMigrator*
    ProfileSyncService::GetBackendMigratorForTest() {
  return migrator_.get();
}

void ProfileSyncService::GetModelSafeRoutingInfo(
    syncer::ModelSafeRoutingInfo* out) const {
  if (backend_.get() && backend_initialized_) {
    backend_->GetModelSafeRoutingInfo(out);
  } else {
    NOTREACHED();
  }
}

base::Value* ProfileSyncService::GetTypeStatusMap() const {
  scoped_ptr<base::ListValue> result(new base::ListValue());

  if (!backend_.get() || !backend_initialized_) {
    return result.release();
  }

  FailedDataTypesHandler::TypeErrorMap error_map =
      failed_data_types_handler_.GetAllErrors();

  ModelTypeSet active_types;
  ModelTypeSet passive_types;
  ModelSafeRoutingInfo routing_info;
  backend_->GetModelSafeRoutingInfo(&routing_info);
  for (ModelSafeRoutingInfo::const_iterator it = routing_info.begin();
       it != routing_info.end(); ++it) {
    if (it->second == syncer::GROUP_PASSIVE) {
      passive_types.Put(it->first);
    } else {
      active_types.Put(it->first);
    }
  }

  SyncBackendHost::Status detailed_status = backend_->GetDetailedStatus();
  ModelTypeSet &throttled_types(detailed_status.throttled_types);
  ModelTypeSet registered = GetRegisteredDataTypes();
  scoped_ptr<base::DictionaryValue> type_status_header(
      new base::DictionaryValue());

  type_status_header->SetString("name", "Model Type");
  type_status_header->SetString("status", "header");
  type_status_header->SetString("value", "Group Type");
  type_status_header->SetString("num_entries", "Total Entries");
  type_status_header->SetString("num_live", "Live Entries");
  result->Append(type_status_header.release());

  scoped_ptr<base::DictionaryValue> type_status;
  for (ModelTypeSet::Iterator it = registered.First(); it.Good(); it.Inc()) {
    ModelType type = it.Get();

    type_status.reset(new base::DictionaryValue());
    type_status->SetString("name", ModelTypeToString(type));

    if (error_map.find(type) != error_map.end()) {
      const syncer::SyncError &error = error_map.find(type)->second;
      DCHECK(error.IsSet());
      std::string error_text = "Error: " + error.location().ToString() +
          ", " + error.message();
      type_status->SetString("status", "error");
      type_status->SetString("value", error_text);
    } else if (throttled_types.Has(type) && passive_types.Has(type)) {
      type_status->SetString("status", "warning");
      type_status->SetString("value", "Passive, Throttled");
    } else if (passive_types.Has(type)) {
      type_status->SetString("status", "warning");
      type_status->SetString("value", "Passive");
    } else if (throttled_types.Has(type)) {
      type_status->SetString("status", "warning");
      type_status->SetString("value", "Throttled");
    } else if (GetRegisteredNonBlockingDataTypes().Has(type)) {
      type_status->SetString("status", "ok");
      type_status->SetString("value", "Non-Blocking");
    } else if (active_types.Has(type)) {
      type_status->SetString("status", "ok");
      type_status->SetString("value", "Active: " +
                             ModelSafeGroupToString(routing_info[type]));
    } else {
      type_status->SetString("status", "warning");
      type_status->SetString("value", "Disabled by User");
    }

    int live_count = detailed_status.num_entries_by_type[type] -
        detailed_status.num_to_delete_entries_by_type[type];
    type_status->SetInteger("num_entries",
                            detailed_status.num_entries_by_type[type]);
    type_status->SetInteger("num_live", live_count);

    result->Append(type_status.release());
  }
  return result.release();
}

void ProfileSyncService::ActivateDataType(
    syncer::ModelType type, syncer::ModelSafeGroup group,
    ChangeProcessor* change_processor) {
  if (!backend_) {
    NOTREACHED();
    return;
  }
  DCHECK(backend_initialized_);
  backend_->ActivateDataType(type, group, change_processor);
}

void ProfileSyncService::DeactivateDataType(syncer::ModelType type) {
  if (!backend_)
    return;
  backend_->DeactivateDataType(type);
}

void ProfileSyncService::ConsumeCachedPassphraseIfPossible() {
  // If no cached passphrase, or sync backend hasn't started up yet, just exit.
  // If the backend isn't running yet, OnBackendInitialized() will call this
  // method again after the backend starts up.
  if (cached_passphrase_.empty() || !sync_initialized())
    return;

  // Backend is up and running, so we can consume the cached passphrase.
  std::string passphrase = cached_passphrase_;
  cached_passphrase_.clear();

  // If we need a passphrase to decrypt data, try the cached passphrase.
  if (passphrase_required_reason() == syncer::REASON_DECRYPTION) {
    if (SetDecryptionPassphrase(passphrase)) {
      DVLOG(1) << "Cached passphrase successfully decrypted pending keys";
      return;
    }
  }

  // If we get here, we don't have pending keys (or at least, the passphrase
  // doesn't decrypt them) - just try to re-encrypt using the encryption
  // passphrase.
  if (!IsUsingSecondaryPassphrase())
    SetEncryptionPassphrase(passphrase, IMPLICIT);
}

void ProfileSyncService::RequestAccessToken() {
  // Only one active request at a time.
  if (access_token_request_ != NULL)
    return;
  request_access_token_retry_timer_.Stop();
  OAuth2TokenService::ScopeSet oauth2_scopes;
  if (profile_->IsManaged()) {
    oauth2_scopes.insert(GaiaConstants::kChromeSyncManagedOAuth2Scope);
  } else {
    oauth2_scopes.insert(GaiaConstants::kChromeSyncOAuth2Scope);
  }

  // Invalidate previous token, otherwise token service will return the same
  // token again.
  const std::string& account_id = signin_->GetAccountIdToUse();
  if (!access_token_.empty()) {
    oauth2_token_service_->InvalidateToken(
        account_id, oauth2_scopes, access_token_);
  }

  access_token_.clear();

  token_request_time_ = base::Time::Now();
  token_receive_time_ = base::Time();
  next_token_request_time_ = base::Time();
  access_token_request_ =
      oauth2_token_service_->StartRequest(account_id, oauth2_scopes, this);
}

void ProfileSyncService::SetEncryptionPassphrase(const std::string& passphrase,
                                                 PassphraseType type) {
  // This should only be called when the backend has been initialized.
  DCHECK(sync_initialized());
  DCHECK(!(type == IMPLICIT && IsUsingSecondaryPassphrase())) <<
      "Data is already encrypted using an explicit passphrase";
  DCHECK(!(type == EXPLICIT &&
           passphrase_required_reason_ == syncer::REASON_DECRYPTION)) <<
         "Can not set explicit passphrase when decryption is needed.";

  DVLOG(1) << "Setting " << (type == EXPLICIT ? "explicit" : "implicit")
           << " passphrase for encryption.";
  if (passphrase_required_reason_ == syncer::REASON_ENCRYPTION) {
    // REASON_ENCRYPTION implies that the cryptographer does not have pending
    // keys. Hence, as long as we're not trying to do an invalid passphrase
    // change (e.g. explicit -> explicit or explicit -> implicit), we know this
    // will succeed. If for some reason a new encryption key arrives via
    // sync later, the SBH will trigger another OnPassphraseRequired().
    passphrase_required_reason_ = syncer::REASON_PASSPHRASE_NOT_REQUIRED;
    NotifyObservers();
  }
  backend_->SetEncryptionPassphrase(passphrase, type == EXPLICIT);
}

bool ProfileSyncService::SetDecryptionPassphrase(
    const std::string& passphrase) {
  if (IsPassphraseRequired()) {
    DVLOG(1) << "Setting passphrase for decryption.";
    return backend_->SetDecryptionPassphrase(passphrase);
  } else {
    NOTREACHED() << "SetDecryptionPassphrase must not be called when "
                    "IsPassphraseRequired() is false.";
    return false;
  }
}

void ProfileSyncService::EnableEncryptEverything() {
  // Tests override sync_initialized() to always return true, so we
  // must check that instead of |backend_initialized_|.
  // TODO(akalin): Fix the above. :/
  DCHECK(sync_initialized());
  // TODO(atwilson): Persist the encryption_pending_ flag to address the various
  // problems around cancelling encryption in the background (crbug.com/119649).
  if (!encrypt_everything_)
    encryption_pending_ = true;
}

bool ProfileSyncService::encryption_pending() const {
  // We may be called during the setup process before we're
  // initialized (via IsEncryptedDatatypeEnabled and
  // IsPassphraseRequiredForDecryption).
  return encryption_pending_;
}

bool ProfileSyncService::EncryptEverythingEnabled() const {
  DCHECK(backend_initialized_);
  return encrypt_everything_ || encryption_pending_;
}

syncer::ModelTypeSet ProfileSyncService::GetEncryptedDataTypes() const {
  DCHECK(encrypted_types_.Has(syncer::PASSWORDS));
  // We may be called during the setup process before we're
  // initialized.  In this case, we default to the sensitive types.
  return encrypted_types_;
}

void ProfileSyncService::OnSyncManagedPrefChange(bool is_sync_managed) {
  NotifyObservers();
  if (is_sync_managed) {
    DisableForUser();
  } else {
    // Sync is no longer disabled by policy. Try starting it up if appropriate.
    startup_controller_.TryStart();
  }
}

void ProfileSyncService::GoogleSigninSucceeded(const std::string& username,
                                               const std::string& password) {
  if (!sync_prefs_.IsStartSuppressed() && !password.empty()) {
    cached_passphrase_ = password;
    // Try to consume the passphrase we just cached. If the sync backend
    // is not running yet, the passphrase will remain cached until the
    // backend starts up.
    ConsumeCachedPassphraseIfPossible();
  }
#if defined(OS_CHROMEOS)
  RefreshSpareBootstrapToken(password);
#endif
  if (!sync_initialized() || GetAuthError().state() != AuthError::NONE) {
    // Track the fact that we're still waiting for auth to complete.
    is_auth_in_progress_ = true;
  }
}

void ProfileSyncService::GoogleSignedOut(const std::string& username) {
  sync_disabled_by_admin_ = false;
  DisableForUser();
}

void ProfileSyncService::AddObserver(
    ProfileSyncServiceBase::Observer* observer) {
  observers_.AddObserver(observer);
}

void ProfileSyncService::RemoveObserver(
    ProfileSyncServiceBase::Observer* observer) {
  observers_.RemoveObserver(observer);
}

void ProfileSyncService::AddProtocolEventObserver(
    browser_sync::ProtocolEventObserver* observer) {
  protocol_event_observers_.AddObserver(observer);
  if (backend_) {
    backend_->RequestBufferedProtocolEventsAndEnableForwarding();
  }
}

void ProfileSyncService::RemoveProtocolEventObserver(
    browser_sync::ProtocolEventObserver* observer) {
  protocol_event_observers_.RemoveObserver(observer);
  if (backend_ && !protocol_event_observers_.might_have_observers()) {
    backend_->DisableProtocolEventForwarding();
  }
}

bool ProfileSyncService::HasObserver(
    ProfileSyncServiceBase::Observer* observer) const {
  return observers_.HasObserver(observer);
}

base::WeakPtr<syncer::JsController> ProfileSyncService::GetJsController() {
  return sync_js_controller_.AsWeakPtr();
}

void ProfileSyncService::SyncEvent(SyncEventCodes code) {
  UMA_HISTOGRAM_ENUMERATION("Sync.EventCodes", code, MAX_SYNC_EVENT_CODE);
}

// static
bool ProfileSyncService::IsSyncEnabled() {
  // We have switches::kEnableSync just in case we need to change back to
  // sync-disabled-by-default on a platform.
  return !CommandLine::ForCurrentProcess()->HasSwitch(switches::kDisableSync);
}

bool ProfileSyncService::IsManaged() const {
  return sync_prefs_.IsManaged() || sync_disabled_by_admin_;
}

bool ProfileSyncService::ShouldPushChanges() {
  // True only after all bootstrapping has succeeded: the sync backend
  // is initialized, all enabled data types are consistent with one
  // another, and no unrecoverable error has transpired.
  if (HasUnrecoverableError())
    return false;

  if (!data_type_manager_)
    return false;

  return data_type_manager_->state() == DataTypeManager::CONFIGURED;
}

void ProfileSyncService::StopAndSuppress() {
  sync_prefs_.SetStartSuppressed(true);
  if (backend_) {
    backend_->UnregisterInvalidationIds();
  }
  ShutdownImpl(browser_sync::SyncBackendHost::STOP_AND_CLAIM_THREAD);
}

bool ProfileSyncService::IsStartSuppressed() const {
  return sync_prefs_.IsStartSuppressed();
}

SigninManagerBase* ProfileSyncService::signin() const {
  if (!signin_)
    return NULL;
  return signin_->GetOriginal();
}

void ProfileSyncService::UnsuppressAndStart() {
  DCHECK(profile_);
  sync_prefs_.SetStartSuppressed(false);
  // Set username in SigninManager, as SigninManager::OnGetUserInfoSuccess
  // is never called for some clients.
  if (signin_.get() &&
      signin_->GetOriginal()->GetAuthenticatedUsername().empty()) {
    signin_->GetOriginal()->SetAuthenticatedUsername(
        profile_->GetPrefs()->GetString(prefs::kGoogleServicesUsername));
  }
  startup_controller_.TryStart();
}

void ProfileSyncService::AcknowledgeSyncedTypes() {
  sync_prefs_.AcknowledgeSyncedTypes(GetRegisteredDataTypes());
}

void ProfileSyncService::ReconfigureDatatypeManager() {
  // If we haven't initialized yet, don't configure the DTM as it could cause
  // association to start before a Directory has even been created.
  if (backend_initialized_) {
    DCHECK(backend_.get());
    ConfigureDataTypeManager();
  } else if (HasUnrecoverableError()) {
    // There is nothing more to configure. So inform the listeners,
    NotifyObservers();

    DVLOG(1) << "ConfigureDataTypeManager not invoked because of an "
             << "Unrecoverable error.";
  } else {
    DVLOG(0) << "ConfigureDataTypeManager not invoked because backend is not "
             << "initialized";
  }
}

const FailedDataTypesHandler& ProfileSyncService::failed_data_types_handler()
    const {
  return failed_data_types_handler_;
}

void ProfileSyncService::OnInternalUnrecoverableError(
    const tracked_objects::Location& from_here,
    const std::string& message,
    bool delete_sync_database,
    UnrecoverableErrorReason reason) {
  DCHECK(!HasUnrecoverableError());
  unrecoverable_error_reason_ = reason;
  OnUnrecoverableErrorImpl(from_here, message, delete_sync_database);
}

bool ProfileSyncService::IsRetryingAccessTokenFetchForTest() const {
  return request_access_token_retry_timer_.IsRunning();
}

std::string ProfileSyncService::GetAccessTokenForTest() const {
  return access_token_;
}

WeakHandle<syncer::JsEventHandler> ProfileSyncService::GetJsEventHandler() {
  return MakeWeakHandle(sync_js_controller_.AsWeakPtr());
}

syncer::SyncableService* ProfileSyncService::GetSessionsSyncableService() {
  return sessions_sync_manager_.get();
}

ProfileSyncService::SyncTokenStatus::SyncTokenStatus()
    : connection_status(syncer::CONNECTION_NOT_ATTEMPTED),
      last_get_token_error(GoogleServiceAuthError::AuthErrorNone()) {}
ProfileSyncService::SyncTokenStatus::~SyncTokenStatus() {}

ProfileSyncService::SyncTokenStatus
ProfileSyncService::GetSyncTokenStatus() const {
  SyncTokenStatus status;
  status.connection_status_update_time = connection_status_update_time_;
  status.connection_status = connection_status_;
  status.token_request_time = token_request_time_;
  status.token_receive_time = token_receive_time_;
  status.last_get_token_error = last_get_token_error_;
  if (request_access_token_retry_timer_.IsRunning())
    status.next_token_request_time = next_token_request_time_;
  return status;
}

void ProfileSyncService::OverrideNetworkResourcesForTest(
    scoped_ptr<syncer::NetworkResources> network_resources) {
  network_resources_ = network_resources.Pass();
}