root/extensions/browser/extension_prefs.cc

DEFINITIONS

1. extension_id_
2. Get
3. JoinPrefs
4. IsBlacklistBitSet
5. IsEvictedEphemeralApp
6. LoadExtensionControlledPrefs
7. GetCurrentTime
8. key_
9. Get
10. Create
11. Create
12. Create
13. Get
14. MakePathRelative
15. MakePathsRelative
16. GetExtensionPref
17. UpdateExtensionPref
18. DeleteExtensionPrefs
19. ReadPrefAsBoolean
20. ReadPrefAsInteger
21. ReadPrefAsString
22. ReadPrefAsList
23. ReadPrefAsDictionary
24. HasPrefForExtension
25. ReadPrefAsURLPatternSet
26. SetExtensionPrefURLPatternSet
27. ReadPrefAsBooleanAndReturn
28. ReadPrefAsPermissionSet
29. CreatePermissionList
30. SetExtensionPrefPermissionSet
31. IncrementAcknowledgePromptCount
32. IsExternalExtensionAcknowledged
33. AcknowledgeExternalExtension
34. IsBlacklistedExtensionAcknowledged
35. AcknowledgeBlacklistedExtension
36. IsExternalInstallFirstRun
37. SetExternalInstallFirstRun
38. HasWipeoutBeenAcknowledged
39. SetWipeoutAcknowledged
40. HasSettingsApiBubbleBeenAcknowledged
41. SetSettingsApiBubbleBeenAcknowledged
42. SetAlertSystemFirstRun
43. ExtensionsBlacklistedByDefault
44. DidExtensionEscalatePermissions
45. SetDidExtensionEscalatePermissions
46. GetDisableReasons
47. AddDisableReason
48. RemoveDisableReason
49. ClearDisableReasons
50. ModifyDisableReason
51. GetBlacklistedExtensions
52. SetExtensionBlacklisted
53. IsExtensionBlacklisted
54. SaveTime
55. ReadTime
56. LastPingDay
57. SetLastPingDay
58. BlacklistLastPingDay
59. SetBlacklistLastPingDay
60. LastActivePingDay
61. SetLastActivePingDay
62. GetActiveBit
63. SetActiveBit
64. MigratePermissions
65. MigrateDisableReasons
66. GetGrantedPermissions
67. AddGrantedPermissions
68. RemoveGrantedPermissions
69. GetActivePermissions
70. SetActivePermissions
71. SetExtensionRunning
72. IsExtensionRunning
73. SetIsActive
74. IsActive
75. IsIncognitoEnabled
76. SetIsIncognitoEnabled
77. AllowFileAccess
78. SetAllowFileAccess
79. HasAllowFileAccessSetting
80. DoesExtensionHaveState
81. IsExternalExtensionUninstalled
82. IsExtensionDisabled
83. GetToolbarOrder
84. SetToolbarOrder
85. GetKnownDisabled
86. SetKnownDisabled
87. OnExtensionInstalled
88. OnExtensionUninstalled
89. SetExtensionState
90. SetExtensionBlacklistState
91. GetExtensionBlacklistState
92. GetVersionString
93. UpdateManifest
94. GetExtensionPath
95. GetInstalledInfoHelper
96. GetInstalledExtensionInfo
97. GetInstalledExtensionsInfo
98. GetUninstalledExtensionsInfo
99. SetDelayedInstallInfo
100. RemoveDelayedInstallInfo
101. FinishDelayedInstallInfo
102. GetDelayedInstallInfo
103. GetDelayedInstallReason
104. GetAllDelayedInstallInfo
105. GetEvictedEphemeralAppsInfo
106. GetEvictedEphemeralAppInfo
107. RemoveEvictedEphemeralApp
108. WasAppDraggedByUser
109. SetAppDraggedByUser
110. IsFromWebStore
111. IsFromBookmark
112. GetCreationFlags
113. GetDelayedInstallCreationFlags
114. WasInstalledByDefault
115. WasInstalledByOem
116. GetInstallTime
117. GetLastLaunchTime
118. SetLastLaunchTime
119. GetExtensions
120. GetExtensionsFrom
121. AddObserver
122. RemoveObserver
123. FixMissingPrefs
124. InitPrefStore
125. HasIncognitoPrefValue
126. GetAllowedInstallSites
127. GetGeometryCache
128. SetGeometryCache
129. GetInstallSignature
130. SetInstallSignature
131. GetInstallParam
132. SetInstallParam
133. extensions_disabled_
134. SetNeedsStorageGarbageCollection
135. NeedsStorageGarbageCollection
136. RegisterProfilePrefs
137. GetUserExtensionPrefIntoContainer
138. SetExtensionPrefFromContainer
139. PopulateExtensionInfoPrefs
140. InitExtensionControlledPrefs
141. FinishExtensionInfoPrefs

// Copyright 2014 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 "extensions/browser/extension_prefs.h"

#include <iterator>

#include "base/command_line.h"
#include "base/prefs/pref_notifier.h"
#include "base/prefs/pref_service.h"
#include "base/strings/string_number_conversions.h"
#include "base/strings/string_util.h"
#include "base/value_conversions.h"
#include "components/user_prefs/pref_registry_syncable.h"
#include "extensions/browser/admin_policy.h"
#include "extensions/browser/app_sorting.h"
#include "extensions/browser/event_router.h"
#include "extensions/browser/extension_pref_store.h"
#include "extensions/browser/extension_prefs_factory.h"
#include "extensions/browser/extension_prefs_observer.h"
#include "extensions/browser/pref_names.h"
#include "extensions/common/feature_switch.h"
#include "extensions/common/manifest.h"
#include "extensions/common/permissions/permission_set.h"
#include "extensions/common/permissions/permissions_info.h"
#include "extensions/common/url_pattern.h"
#include "extensions/common/user_script.h"
#include "ui/base/l10n/l10n_util.h"

using base::Value;
using base::DictionaryValue;
using base::ListValue;

namespace extensions {

namespace {

// Additional preferences keys, which are not needed by external clients.

// True if this extension is running. Note this preference stops getting updated
// during Chrome shutdown (and won't be updated on a browser crash) and so can
// be used at startup to determine whether the extension was running when Chrome
// was last terminated.
const char kPrefRunning[] = "running";

// Whether this extension had windows when it was last running.
const char kIsActive[] = "is_active";

// Where an extension was installed from. (see Manifest::Location)
const char kPrefLocation[] = "location";

// Enabled, disabled, killed, etc. (see Extension::State)
const char kPrefState[] = "state";

// The path to the current version's manifest file.
const char kPrefPath[] = "path";

// The dictionary containing the extension's manifest.
const char kPrefManifest[] = "manifest";

// The version number.
const char kPrefVersion[] = "manifest.version";

// Indicates whether an extension is blacklisted.
const char kPrefBlacklist[] = "blacklist";

// If extension is greylisted.
const char kPrefBlacklistState[] = "blacklist_state";

// The count of how many times we prompted the user to acknowledge an
// extension.
const char kPrefAcknowledgePromptCount[] = "ack_prompt_count";

// Indicates whether the user has acknowledged various types of extensions.
const char kPrefExternalAcknowledged[] = "ack_external";
const char kPrefBlacklistAcknowledged[] = "ack_blacklist";
const char kPrefWipeoutAcknowledged[] = "ack_wiped";
const char kPrefSettingsBubbleAcknowledged[] = "ack_settings_bubble";

// Indicates whether the external extension was installed during the first
// run of this profile.
const char kPrefExternalInstallFirstRun[] = "external_first_run";

// Indicates whether to show an install warning when the user enables.
const char kExtensionDidEscalatePermissions[] = "install_warning_on_enable";

// DO NOT USE, use kPrefDisableReasons instead.
// Indicates whether the extension was updated while it was disabled.
const char kDeprecatedPrefDisableReason[] = "disable_reason";

// A bitmask of all the reasons an extension is disabled.
const char kPrefDisableReasons[] = "disable_reasons";

// The key for a serialized Time value indicating the start of the day (from the
// server's perspective) an extension last included a "ping" parameter during
// its update check.
const char kLastPingDay[] = "lastpingday";

// Similar to kLastPingDay, but for "active" instead of "rollcall" pings.
const char kLastActivePingDay[] = "last_active_pingday";

// A bit we use to keep track of whether we need to do an "active" ping.
const char kActiveBit[] = "active_bit";

// Path for settings specific to blacklist update.
const char kExtensionsBlacklistUpdate[] = "extensions.blacklistupdate";

// Path for the delayed install info dictionary preference. The actual string
// value is a legacy artifact for when delayed installs only pertained to
// updates that were waiting for idle.
const char kDelayedInstallInfo[] = "idle_install_info";

// Reason why the extension's install was delayed.
const char kDelayedInstallReason[] = "delay_install_reason";

// Path for the suggested page ordinal of a delayed extension install.
const char kPrefSuggestedPageOrdinal[] = "suggested_page_ordinal";

// A preference that, if true, will allow this extension to run in incognito
// mode.
const char kPrefIncognitoEnabled[] = "incognito";

// A preference to control whether an extension is allowed to inject script in
// pages with file URLs.
const char kPrefAllowFileAccess[] = "newAllowFileAccess";
// TODO(jstritar): As part of fixing http://crbug.com/91577, we revoked all
// extension file access by renaming the pref. We should eventually clean up
// the old flag and possibly go back to that name.
// const char kPrefAllowFileAccessOld[] = "allowFileAccess";

// A preference specifying if the user dragged the app on the NTP.
const char kPrefUserDraggedApp[] = "user_dragged_app_ntp";

// Preferences that hold which permissions the user has granted the extension.
// We explicitly keep track of these so that extensions can contain unknown
// permissions, for backwards compatibility reasons, and we can still prompt
// the user to accept them once recognized. We store the active permission
// permissions because they may differ from those defined in the manifest.
const char kPrefActivePermissions[] = "active_permissions";
const char kPrefGrantedPermissions[] = "granted_permissions";

// The preference names for PermissionSet values.
const char kPrefAPIs[] = "api";
const char kPrefManifestPermissions[] = "manifest_permissions";
const char kPrefExplicitHosts[] = "explicit_host";
const char kPrefScriptableHosts[] = "scriptable_host";

// The preference names for the old granted permissions scheme.
const char kPrefOldGrantedFullAccess[] = "granted_permissions.full";
const char kPrefOldGrantedHosts[] = "granted_permissions.host";
const char kPrefOldGrantedAPIs[] = "granted_permissions.api";

// A preference that indicates when an extension was installed.
const char kPrefInstallTime[] = "install_time";

// A preference which saves the creation flags for extensions.
const char kPrefCreationFlags[] = "creation_flags";

// A preference that indicates whether the extension was installed from the
// Chrome Web Store.
const char kPrefFromWebStore[] = "from_webstore";

// A preference that indicates whether the extension was installed from a
// mock App created from a bookmark.
const char kPrefFromBookmark[] = "from_bookmark";

// A preference that indicates whether the extension was installed as a
// default app.
const char kPrefWasInstalledByDefault[] = "was_installed_by_default";

// A preference that indicates whether the extension was installed as an
// OEM app.
const char kPrefWasInstalledByOem[] = "was_installed_by_oem";

// Key for Geometry Cache preference.
const char kPrefGeometryCache[] = "geometry_cache";

// A preference that indicates when an extension is last launched.
const char kPrefLastLaunchTime[] = "last_launch_time";

// A preference that marks an ephemeral app that was evicted from the cache.
// Their data is retained and garbage collected when inactive for a long period
// of time.
const char kPrefEvictedEphemeralApp[] = "evicted_ephemeral_app";

// Am installation parameter bundled with an extension.
const char kPrefInstallParam[] = "install_parameter";

// A list of installed ids and a signature.
const char kInstallSignature[] = "extensions.install_signature";

// Provider of write access to a dictionary storing extension prefs.
class ScopedExtensionPrefUpdate : public DictionaryPrefUpdate {
 public:
  ScopedExtensionPrefUpdate(PrefService* service,
                            const std::string& extension_id) :
    DictionaryPrefUpdate(service, pref_names::kExtensions),
    extension_id_(extension_id) {}

  virtual ~ScopedExtensionPrefUpdate() {
  }

  // DictionaryPrefUpdate overrides:
  virtual base::DictionaryValue* Get() OVERRIDE {
    base::DictionaryValue* dict = DictionaryPrefUpdate::Get();
    base::DictionaryValue* extension = NULL;
    if (!dict->GetDictionary(extension_id_, &extension)) {
      // Extension pref does not exist, create it.
      extension = new base::DictionaryValue();
      dict->SetWithoutPathExpansion(extension_id_, extension);
    }
    return extension;
  }

 private:
  const std::string extension_id_;

  DISALLOW_COPY_AND_ASSIGN(ScopedExtensionPrefUpdate);
};

std::string JoinPrefs(const std::string& parent, const char* child) {
  return parent + "." + child;
}

// Checks if kPrefBlacklist is set to true in the base::DictionaryValue.
// Return false if the value is false or kPrefBlacklist does not exist.
// This is used to decide if an extension is blacklisted.
bool IsBlacklistBitSet(const base::DictionaryValue* ext) {
  bool bool_value;
  return ext->GetBoolean(kPrefBlacklist, &bool_value) && bool_value;
}

bool IsEvictedEphemeralApp(const base::DictionaryValue* ext) {
  bool bool_value;
  return ext->GetBoolean(kPrefEvictedEphemeralApp, &bool_value) && bool_value;
}

void LoadExtensionControlledPrefs(ExtensionPrefs* prefs,
                                  ExtensionPrefValueMap* value_map,
                                  const std::string& extension_id,
                                  ExtensionPrefsScope scope) {
  std::string scope_string;
  if (!pref_names::ScopeToPrefName(scope, &scope_string))
    return;
  std::string key = extension_id + "." + scope_string;

  const base::DictionaryValue* source_dict =
      prefs->pref_service()->GetDictionary(pref_names::kExtensions);
  const base::DictionaryValue* preferences = NULL;
  if (!source_dict->GetDictionary(key, &preferences))
    return;

  for (base::DictionaryValue::Iterator iter(*preferences); !iter.IsAtEnd();
       iter.Advance()) {
    value_map->SetExtensionPref(
        extension_id, iter.key(), scope, iter.value().DeepCopy());
  }
}

}  // namespace

//
// TimeProvider
//

ExtensionPrefs::TimeProvider::TimeProvider() {
}

ExtensionPrefs::TimeProvider::~TimeProvider() {
}

base::Time ExtensionPrefs::TimeProvider::GetCurrentTime() const {
  return base::Time::Now();
}

//
// ScopedUpdate
//
template <typename T, base::Value::Type type_enum_value>
ExtensionPrefs::ScopedUpdate<T, type_enum_value>::ScopedUpdate(
    ExtensionPrefs* prefs,
    const std::string& extension_id,
    const std::string& key)
    : update_(prefs->pref_service(), pref_names::kExtensions),
      extension_id_(extension_id),
      key_(key) {
  DCHECK(Extension::IdIsValid(extension_id_));
}

template <typename T, base::Value::Type type_enum_value>
ExtensionPrefs::ScopedUpdate<T, type_enum_value>::~ScopedUpdate() {
}

template <typename T, base::Value::Type type_enum_value>
T* ExtensionPrefs::ScopedUpdate<T, type_enum_value>::Get() {
  base::DictionaryValue* dict = update_.Get();
  base::DictionaryValue* extension = NULL;
  base::Value* key_value = NULL;
  if (!dict->GetDictionary(extension_id_, &extension) ||
      !extension->Get(key_, &key_value)) {
    return NULL;
  }
  return key_value->GetType() == type_enum_value ?
      static_cast<T*>(key_value) :
      NULL;
}

template <typename T, base::Value::Type type_enum_value>
T* ExtensionPrefs::ScopedUpdate<T, type_enum_value>::Create() {
  base::DictionaryValue* dict = update_.Get();
  base::DictionaryValue* extension = NULL;
  base::Value* key_value = NULL;
  T* value_as_t = NULL;
  if (!dict->GetDictionary(extension_id_, &extension)) {
    extension = new base::DictionaryValue;
    dict->SetWithoutPathExpansion(extension_id_, extension);
  }
  if (!extension->Get(key_, &key_value)) {
    value_as_t = new T;
    extension->SetWithoutPathExpansion(key_, value_as_t);
  } else {
    CHECK(key_value->GetType() == type_enum_value);
    value_as_t = static_cast<T*>(key_value);
  }
  return value_as_t;
}

// Explicit instantiations for Dictionary and List value types.
template class ExtensionPrefs::ScopedUpdate<base::DictionaryValue,
                                            base::Value::TYPE_DICTIONARY>;
template class ExtensionPrefs::ScopedUpdate<base::ListValue,
                                            base::Value::TYPE_LIST>;

//
// ExtensionPrefs
//

// static
ExtensionPrefs* ExtensionPrefs::Create(
    PrefService* prefs,
    const base::FilePath& root_dir,
    ExtensionPrefValueMap* extension_pref_value_map,
    scoped_ptr<AppSorting> app_sorting,
    bool extensions_disabled,
    const std::vector<ExtensionPrefsObserver*>& early_observers) {
  return ExtensionPrefs::Create(prefs,
                                root_dir,
                                extension_pref_value_map,
                                app_sorting.Pass(),
                                extensions_disabled,
                                early_observers,
                                make_scoped_ptr(new TimeProvider()));
}

// static
ExtensionPrefs* ExtensionPrefs::Create(
    PrefService* pref_service,
    const base::FilePath& root_dir,
    ExtensionPrefValueMap* extension_pref_value_map,
    scoped_ptr<AppSorting> app_sorting,
    bool extensions_disabled,
    const std::vector<ExtensionPrefsObserver*>& early_observers,
    scoped_ptr<TimeProvider> time_provider) {
  return new ExtensionPrefs(pref_service,
                            root_dir,
                            extension_pref_value_map,
                            app_sorting.Pass(),
                            time_provider.Pass(),
                            extensions_disabled,
                            early_observers);
}

ExtensionPrefs::~ExtensionPrefs() {
}

// static
ExtensionPrefs* ExtensionPrefs::Get(content::BrowserContext* context) {
  return ExtensionPrefsFactory::GetInstance()->GetForBrowserContext(context);
}

static base::FilePath::StringType MakePathRelative(const base::FilePath& parent,
                                             const base::FilePath& child) {
  if (!parent.IsParent(child))
    return child.value();

  base::FilePath::StringType retval = child.value().substr(
      parent.value().length());
  if (base::FilePath::IsSeparator(retval[0]))
    return retval.substr(1);
  else
    return retval;
}

void ExtensionPrefs::MakePathsRelative() {
  const base::DictionaryValue* dict =
      prefs_->GetDictionary(pref_names::kExtensions);
  if (!dict || dict->empty())
    return;

  // Collect all extensions ids with absolute paths in |absolute_keys|.
  std::set<std::string> absolute_keys;
  for (base::DictionaryValue::Iterator i(*dict); !i.IsAtEnd(); i.Advance()) {
    const base::DictionaryValue* extension_dict = NULL;
    if (!i.value().GetAsDictionary(&extension_dict))
      continue;
    int location_value;
    if (extension_dict->GetInteger(kPrefLocation, &location_value) &&
        Manifest::IsUnpackedLocation(
            static_cast<Manifest::Location>(location_value))) {
      // Unpacked extensions can have absolute paths.
      continue;
    }
    base::FilePath::StringType path_string;
    if (!extension_dict->GetString(kPrefPath, &path_string))
      continue;
    base::FilePath path(path_string);
    if (path.IsAbsolute())
      absolute_keys.insert(i.key());
  }
  if (absolute_keys.empty())
    return;

  // Fix these paths.
  DictionaryPrefUpdate update(prefs_, pref_names::kExtensions);
  base::DictionaryValue* update_dict = update.Get();
  for (std::set<std::string>::iterator i = absolute_keys.begin();
       i != absolute_keys.end(); ++i) {
    base::DictionaryValue* extension_dict = NULL;
    if (!update_dict->GetDictionaryWithoutPathExpansion(*i, &extension_dict)) {
      NOTREACHED() << "Control should never reach here for extension " << *i;
      continue;
    }
    base::FilePath::StringType path_string;
    extension_dict->GetString(kPrefPath, &path_string);
    base::FilePath path(path_string);
    extension_dict->SetString(kPrefPath,
        MakePathRelative(install_directory_, path));
  }
}

const base::DictionaryValue* ExtensionPrefs::GetExtensionPref(
    const std::string& extension_id) const {
  const base::DictionaryValue* extensions =
      prefs_->GetDictionary(pref_names::kExtensions);
  const base::DictionaryValue* extension_dict = NULL;
  if (!extensions ||
      !extensions->GetDictionary(extension_id, &extension_dict)) {
    return NULL;
  }
  return extension_dict;
}

void ExtensionPrefs::UpdateExtensionPref(const std::string& extension_id,
                                         const std::string& key,
                                         base::Value* data_value) {
  if (!Extension::IdIsValid(extension_id)) {
    NOTREACHED() << "Invalid extension_id " << extension_id;
    return;
  }
  ScopedExtensionPrefUpdate update(prefs_, extension_id);
  if (data_value)
    update->Set(key, data_value);
  else
    update->Remove(key, NULL);
}

void ExtensionPrefs::DeleteExtensionPrefs(const std::string& extension_id) {
  extension_pref_value_map_->UnregisterExtension(extension_id);
  FOR_EACH_OBSERVER(ExtensionPrefsObserver,
                    observer_list_,
                    OnExtensionPrefsDeleted(extension_id));
  DictionaryPrefUpdate update(prefs_, pref_names::kExtensions);
  base::DictionaryValue* dict = update.Get();
  dict->Remove(extension_id, NULL);
}

bool ExtensionPrefs::ReadPrefAsBoolean(const std::string& extension_id,
                                       const std::string& pref_key,
                                       bool* out_value) const {
  const base::DictionaryValue* ext = GetExtensionPref(extension_id);
  if (!ext || !ext->GetBoolean(pref_key, out_value))
    return false;

  return true;
}

bool ExtensionPrefs::ReadPrefAsInteger(const std::string& extension_id,
                                       const std::string& pref_key,
                                       int* out_value) const {
  const base::DictionaryValue* ext = GetExtensionPref(extension_id);
  if (!ext || !ext->GetInteger(pref_key, out_value))
    return false;

  return true;
}

bool ExtensionPrefs::ReadPrefAsString(const std::string& extension_id,
                                      const std::string& pref_key,
                                      std::string* out_value) const {
  const base::DictionaryValue* ext = GetExtensionPref(extension_id);
  if (!ext || !ext->GetString(pref_key, out_value))
    return false;

  return true;
}

bool ExtensionPrefs::ReadPrefAsList(const std::string& extension_id,
                                    const std::string& pref_key,
                                    const base::ListValue** out_value) const {
  const base::DictionaryValue* ext = GetExtensionPref(extension_id);
  const base::ListValue* out = NULL;
  if (!ext || !ext->GetList(pref_key, &out))
    return false;
  if (out_value)
    *out_value = out;

  return true;
}

bool ExtensionPrefs::ReadPrefAsDictionary(
    const std::string& extension_id,
    const std::string& pref_key,
    const base::DictionaryValue** out_value) const {
  const base::DictionaryValue* ext = GetExtensionPref(extension_id);
  const base::DictionaryValue* out = NULL;
  if (!ext || !ext->GetDictionary(pref_key, &out))
    return false;
  if (out_value)
    *out_value = out;

  return true;
}

bool ExtensionPrefs::HasPrefForExtension(
    const std::string& extension_id) const {
  return GetExtensionPref(extension_id) != NULL;
}

bool ExtensionPrefs::ReadPrefAsURLPatternSet(const std::string& extension_id,
                                             const std::string& pref_key,
                                             URLPatternSet* result,
                                             int valid_schemes) {
  const base::ListValue* value = NULL;
  if (!ReadPrefAsList(extension_id, pref_key, &value))
    return false;

  bool allow_file_access = AllowFileAccess(extension_id);
  return result->Populate(*value, valid_schemes, allow_file_access, NULL);
}

void ExtensionPrefs::SetExtensionPrefURLPatternSet(
    const std::string& extension_id,
    const std::string& pref_key,
    const URLPatternSet& new_value) {
  UpdateExtensionPref(extension_id, pref_key, new_value.ToValue().release());
}

bool ExtensionPrefs::ReadPrefAsBooleanAndReturn(
    const std::string& extension_id,
    const std::string& pref_key) const {
  bool out_value = false;
  return ReadPrefAsBoolean(extension_id, pref_key, &out_value) && out_value;
}

PermissionSet* ExtensionPrefs::ReadPrefAsPermissionSet(
    const std::string& extension_id,
    const std::string& pref_key) {
  if (!GetExtensionPref(extension_id))
    return NULL;

  // Retrieve the API permissions. Please refer SetExtensionPrefPermissionSet()
  // for api_values format.
  APIPermissionSet apis;
  const base::ListValue* api_values = NULL;
  std::string api_pref = JoinPrefs(pref_key, kPrefAPIs);
  if (ReadPrefAsList(extension_id, api_pref, &api_values)) {
    APIPermissionSet::ParseFromJSON(api_values,
                                    APIPermissionSet::kAllowInternalPermissions,
                                    &apis, NULL, NULL);
  }

  // Retrieve the Manifest Keys permissions. Please refer to
  // |SetExtensionPrefPermissionSet| for manifest_permissions_values format.
  ManifestPermissionSet manifest_permissions;
  const base::ListValue* manifest_permissions_values = NULL;
  std::string manifest_permission_pref =
      JoinPrefs(pref_key, kPrefManifestPermissions);
  if (ReadPrefAsList(extension_id, manifest_permission_pref,
                     &manifest_permissions_values)) {
    ManifestPermissionSet::ParseFromJSON(
        manifest_permissions_values, &manifest_permissions, NULL, NULL);
  }

  // Retrieve the explicit host permissions.
  URLPatternSet explicit_hosts;
  ReadPrefAsURLPatternSet(
      extension_id, JoinPrefs(pref_key, kPrefExplicitHosts),
      &explicit_hosts, Extension::kValidHostPermissionSchemes);

  // Retrieve the scriptable host permissions.
  URLPatternSet scriptable_hosts;
  ReadPrefAsURLPatternSet(
      extension_id, JoinPrefs(pref_key, kPrefScriptableHosts),
      &scriptable_hosts, UserScript::ValidUserScriptSchemes());

  return new PermissionSet(
      apis, manifest_permissions, explicit_hosts, scriptable_hosts);
}

// Set the API or Manifest permissions.
// The format of api_values is:
// [ "permission_name1",   // permissions do not support detail.
//   "permission_name2",
//   {"permission_name3": value },
//   // permission supports detail, permission detail will be stored in value.
//   ...
// ]
template<typename T>
static base::ListValue* CreatePermissionList(const T& permissions) {
  base::ListValue* values = new base::ListValue();
  for (typename T::const_iterator i = permissions.begin();
      i != permissions.end(); ++i) {
    scoped_ptr<base::Value> detail(i->ToValue());
    if (detail) {
      base::DictionaryValue* tmp = new base::DictionaryValue();
      tmp->Set(i->name(), detail.release());
      values->Append(tmp);
    } else {
      values->Append(new base::StringValue(i->name()));
    }
  }
  return values;
}

void ExtensionPrefs::SetExtensionPrefPermissionSet(
    const std::string& extension_id,
    const std::string& pref_key,
    const PermissionSet* new_value) {
  std::string api_pref = JoinPrefs(pref_key, kPrefAPIs);
  base::ListValue* api_values = CreatePermissionList(new_value->apis());
  UpdateExtensionPref(extension_id, api_pref, api_values);

  std::string manifest_permissions_pref =
      JoinPrefs(pref_key, kPrefManifestPermissions);
  base::ListValue* manifest_permissions_values = CreatePermissionList(
      new_value->manifest_permissions());
  UpdateExtensionPref(extension_id,
                      manifest_permissions_pref,
                      manifest_permissions_values);

  // Set the explicit host permissions.
  if (!new_value->explicit_hosts().is_empty()) {
    SetExtensionPrefURLPatternSet(extension_id,
                                  JoinPrefs(pref_key, kPrefExplicitHosts),
                                  new_value->explicit_hosts());
  }

  // Set the scriptable host permissions.
  if (!new_value->scriptable_hosts().is_empty()) {
    SetExtensionPrefURLPatternSet(extension_id,
                                  JoinPrefs(pref_key, kPrefScriptableHosts),
                                  new_value->scriptable_hosts());
  }
}

int ExtensionPrefs::IncrementAcknowledgePromptCount(
    const std::string& extension_id) {
  int count = 0;
  ReadPrefAsInteger(extension_id, kPrefAcknowledgePromptCount, &count);
  ++count;
  UpdateExtensionPref(extension_id, kPrefAcknowledgePromptCount,
                      new base::FundamentalValue(count));
  return count;
}

bool ExtensionPrefs::IsExternalExtensionAcknowledged(
    const std::string& extension_id) {
  return ReadPrefAsBooleanAndReturn(extension_id, kPrefExternalAcknowledged);
}

void ExtensionPrefs::AcknowledgeExternalExtension(
    const std::string& extension_id) {
  DCHECK(Extension::IdIsValid(extension_id));
  UpdateExtensionPref(extension_id, kPrefExternalAcknowledged,
                      new base::FundamentalValue(true));
  UpdateExtensionPref(extension_id, kPrefAcknowledgePromptCount, NULL);
}

bool ExtensionPrefs::IsBlacklistedExtensionAcknowledged(
    const std::string& extension_id) {
  return ReadPrefAsBooleanAndReturn(extension_id, kPrefBlacklistAcknowledged);
}

void ExtensionPrefs::AcknowledgeBlacklistedExtension(
    const std::string& extension_id) {
  DCHECK(Extension::IdIsValid(extension_id));
  UpdateExtensionPref(extension_id, kPrefBlacklistAcknowledged,
                      new base::FundamentalValue(true));
  UpdateExtensionPref(extension_id, kPrefAcknowledgePromptCount, NULL);
}

bool ExtensionPrefs::IsExternalInstallFirstRun(
    const std::string& extension_id) {
  return ReadPrefAsBooleanAndReturn(extension_id, kPrefExternalInstallFirstRun);
}

void ExtensionPrefs::SetExternalInstallFirstRun(
    const std::string& extension_id) {
  DCHECK(Extension::IdIsValid(extension_id));
  UpdateExtensionPref(extension_id, kPrefExternalInstallFirstRun,
                      new base::FundamentalValue(true));
}

bool ExtensionPrefs::HasWipeoutBeenAcknowledged(
    const std::string& extension_id) {
  return ReadPrefAsBooleanAndReturn(extension_id, kPrefWipeoutAcknowledged);
}

void ExtensionPrefs::SetWipeoutAcknowledged(
    const std::string& extension_id,
    bool value) {
  UpdateExtensionPref(extension_id, kPrefWipeoutAcknowledged,
                      value ? base::Value::CreateBooleanValue(value) : NULL);
}

bool ExtensionPrefs::HasSettingsApiBubbleBeenAcknowledged(
    const std::string& extension_id) {
  return ReadPrefAsBooleanAndReturn(extension_id,
                                    kPrefSettingsBubbleAcknowledged);
}

void ExtensionPrefs::SetSettingsApiBubbleBeenAcknowledged(
    const std::string& extension_id,
    bool value) {
  UpdateExtensionPref(extension_id,
                      kPrefSettingsBubbleAcknowledged,
                      value ? base::Value::CreateBooleanValue(value) : NULL);
}

bool ExtensionPrefs::SetAlertSystemFirstRun() {
  if (prefs_->GetBoolean(pref_names::kAlertsInitialized)) {
    return true;
  }
  prefs_->SetBoolean(pref_names::kAlertsInitialized, true);
  return false;
}

bool ExtensionPrefs::ExtensionsBlacklistedByDefault() const {
  return admin_policy::BlacklistedByDefault(
      prefs_->GetList(pref_names::kInstallDenyList));
}

bool ExtensionPrefs::DidExtensionEscalatePermissions(
    const std::string& extension_id) {
  return ReadPrefAsBooleanAndReturn(extension_id,
                                    kExtensionDidEscalatePermissions);
}

void ExtensionPrefs::SetDidExtensionEscalatePermissions(
    const Extension* extension, bool did_escalate) {
  UpdateExtensionPref(extension->id(), kExtensionDidEscalatePermissions,
                      new base::FundamentalValue(did_escalate));
}

int ExtensionPrefs::GetDisableReasons(const std::string& extension_id) const {
  int value = -1;
  if (ReadPrefAsInteger(extension_id, kPrefDisableReasons, &value) &&
      value >= 0) {
    return value;
  }
  return Extension::DISABLE_NONE;
}

void ExtensionPrefs::AddDisableReason(const std::string& extension_id,
                                      Extension::DisableReason disable_reason) {
  ModifyDisableReason(extension_id, disable_reason, DISABLE_REASON_ADD);
}

void ExtensionPrefs::RemoveDisableReason(
    const std::string& extension_id,
    Extension::DisableReason disable_reason) {
  ModifyDisableReason(extension_id, disable_reason, DISABLE_REASON_REMOVE);
}

void ExtensionPrefs::ClearDisableReasons(const std::string& extension_id) {
  ModifyDisableReason(
      extension_id, Extension::DISABLE_NONE, DISABLE_REASON_CLEAR);
}

void ExtensionPrefs::ModifyDisableReason(const std::string& extension_id,
                                         Extension::DisableReason reason,
                                         DisableReasonChange change) {
  int old_value = GetDisableReasons(extension_id);
  int new_value = old_value;
  switch (change) {
    case DISABLE_REASON_ADD:
      new_value |= static_cast<int>(reason);
      break;
    case DISABLE_REASON_REMOVE:
      new_value &= ~static_cast<int>(reason);
      break;
    case DISABLE_REASON_CLEAR:
      new_value = Extension::DISABLE_NONE;
      break;
  }

  if (old_value == new_value)  // no change, return.
    return;

  if (new_value == Extension::DISABLE_NONE) {
    UpdateExtensionPref(extension_id, kPrefDisableReasons, NULL);
  } else {
    UpdateExtensionPref(extension_id,
                        kPrefDisableReasons,
                        new base::FundamentalValue(new_value));
  }

  FOR_EACH_OBSERVER(ExtensionPrefsObserver,
                    observer_list_,
                    OnExtensionDisableReasonsChanged(extension_id, new_value));
}

std::set<std::string> ExtensionPrefs::GetBlacklistedExtensions() {
  std::set<std::string> ids;

  const base::DictionaryValue* extensions =
      prefs_->GetDictionary(pref_names::kExtensions);
  if (!extensions)
    return ids;

  for (base::DictionaryValue::Iterator it(*extensions);
       !it.IsAtEnd(); it.Advance()) {
    if (!it.value().IsType(base::Value::TYPE_DICTIONARY)) {
      NOTREACHED() << "Invalid pref for extension " << it.key();
      continue;
    }
    if (IsBlacklistBitSet(
            static_cast<const base::DictionaryValue*>(&it.value()))) {
      ids.insert(it.key());
    }
  }

  return ids;
}

void ExtensionPrefs::SetExtensionBlacklisted(const std::string& extension_id,
                                             bool is_blacklisted) {
  bool currently_blacklisted = IsExtensionBlacklisted(extension_id);
  if (is_blacklisted == currently_blacklisted)
    return;

  // Always make sure the "acknowledged" bit is cleared since the blacklist bit
  // is changing.
  UpdateExtensionPref(extension_id, kPrefBlacklistAcknowledged, NULL);

  if (is_blacklisted) {
    UpdateExtensionPref(extension_id,
                        kPrefBlacklist,
                        new base::FundamentalValue(true));
  } else {
    UpdateExtensionPref(extension_id, kPrefBlacklist, NULL);
    const base::DictionaryValue* dict = GetExtensionPref(extension_id);
    if (dict && dict->empty())
      DeleteExtensionPrefs(extension_id);
  }
}

bool ExtensionPrefs::IsExtensionBlacklisted(const std::string& id) const {
  const base::DictionaryValue* ext_prefs = GetExtensionPref(id);
  return ext_prefs && IsBlacklistBitSet(ext_prefs);
}

namespace {

// Serializes |time| as a string value mapped to |key| in |dictionary|.
void SaveTime(base::DictionaryValue* dictionary,
              const char* key,
              const base::Time& time) {
  if (!dictionary)
    return;
  std::string string_value = base::Int64ToString(time.ToInternalValue());
  dictionary->SetString(key, string_value);
}

// The opposite of SaveTime. If |key| is not found, this returns an empty Time
// (is_null() will return true).
base::Time ReadTime(const base::DictionaryValue* dictionary, const char* key) {
  if (!dictionary)
    return base::Time();
  std::string string_value;
  int64 value;
  if (dictionary->GetString(key, &string_value)) {
    if (base::StringToInt64(string_value, &value)) {
      return base::Time::FromInternalValue(value);
    }
  }
  return base::Time();
}

}  // namespace

base::Time ExtensionPrefs::LastPingDay(const std::string& extension_id) const {
  DCHECK(Extension::IdIsValid(extension_id));
  return ReadTime(GetExtensionPref(extension_id), kLastPingDay);
}

void ExtensionPrefs::SetLastPingDay(const std::string& extension_id,
                                    const base::Time& time) {
  DCHECK(Extension::IdIsValid(extension_id));
  ScopedExtensionPrefUpdate update(prefs_, extension_id);
  SaveTime(update.Get(), kLastPingDay, time);
}

base::Time ExtensionPrefs::BlacklistLastPingDay() const {
  return ReadTime(prefs_->GetDictionary(kExtensionsBlacklistUpdate),
                  kLastPingDay);
}

void ExtensionPrefs::SetBlacklistLastPingDay(const base::Time& time) {
  DictionaryPrefUpdate update(prefs_, kExtensionsBlacklistUpdate);
  SaveTime(update.Get(), kLastPingDay, time);
}

base::Time ExtensionPrefs::LastActivePingDay(const std::string& extension_id) {
  DCHECK(Extension::IdIsValid(extension_id));
  return ReadTime(GetExtensionPref(extension_id), kLastActivePingDay);
}

void ExtensionPrefs::SetLastActivePingDay(const std::string& extension_id,
                                          const base::Time& time) {
  DCHECK(Extension::IdIsValid(extension_id));
  ScopedExtensionPrefUpdate update(prefs_, extension_id);
  SaveTime(update.Get(), kLastActivePingDay, time);
}

bool ExtensionPrefs::GetActiveBit(const std::string& extension_id) {
  const base::DictionaryValue* dictionary = GetExtensionPref(extension_id);
  bool result = false;
  if (dictionary && dictionary->GetBoolean(kActiveBit, &result))
    return result;
  return false;
}

void ExtensionPrefs::SetActiveBit(const std::string& extension_id,
                                  bool active) {
  UpdateExtensionPref(extension_id, kActiveBit,
                      new base::FundamentalValue(active));
}

void ExtensionPrefs::MigratePermissions(const ExtensionIdList& extension_ids) {
  PermissionsInfo* info = PermissionsInfo::GetInstance();
  for (ExtensionIdList::const_iterator ext_id =
       extension_ids.begin(); ext_id != extension_ids.end(); ++ext_id) {
    // An extension's granted permissions need to be migrated if the
    // full_access bit is present. This bit was always present in the previous
    // scheme and is never present now.
    bool full_access;
    const base::DictionaryValue* ext = GetExtensionPref(*ext_id);
    if (!ext || !ext->GetBoolean(kPrefOldGrantedFullAccess, &full_access))
      continue;

    // Remove the full access bit (empty list will get trimmed).
    UpdateExtensionPref(
        *ext_id, kPrefOldGrantedFullAccess, new base::ListValue());

    // Add the plugin permission if the full access bit was set.
    if (full_access) {
      const base::ListValue* apis = NULL;
      base::ListValue* new_apis = NULL;

      std::string granted_apis = JoinPrefs(kPrefGrantedPermissions, kPrefAPIs);
      if (ext->GetList(kPrefOldGrantedAPIs, &apis))
        new_apis = apis->DeepCopy();
      else
        new_apis = new base::ListValue();

      std::string plugin_name = info->GetByID(APIPermission::kPlugin)->name();
      new_apis->Append(new base::StringValue(plugin_name));
      UpdateExtensionPref(*ext_id, granted_apis, new_apis);
    }

    // The granted permissions originally only held the effective hosts,
    // which are a combination of host and user script host permissions.
    // We now maintain these lists separately. For migration purposes, it
    // does not matter how we treat the old effective hosts as long as the
    // new effective hosts will be the same, so we move them to explicit
    // host permissions.
    const base::ListValue* hosts = NULL;
    std::string explicit_hosts =
        JoinPrefs(kPrefGrantedPermissions, kPrefExplicitHosts);
    if (ext->GetList(kPrefOldGrantedHosts, &hosts)) {
      UpdateExtensionPref(
          *ext_id, explicit_hosts, hosts->DeepCopy());

      // We can get rid of the old one by setting it to an empty list.
      UpdateExtensionPref(*ext_id, kPrefOldGrantedHosts, new base::ListValue());
    }
  }
}

void ExtensionPrefs::MigrateDisableReasons(
    const ExtensionIdList& extension_ids) {
  for (ExtensionIdList::const_iterator ext_id =
       extension_ids.begin(); ext_id != extension_ids.end(); ++ext_id) {
    int value = -1;
    if (ReadPrefAsInteger(*ext_id, kDeprecatedPrefDisableReason, &value)) {
      int new_value = Extension::DISABLE_NONE;
      switch (value) {
        case Extension::DEPRECATED_DISABLE_USER_ACTION:
          new_value = Extension::DISABLE_USER_ACTION;
          break;
        case Extension::DEPRECATED_DISABLE_PERMISSIONS_INCREASE:
          new_value = Extension::DISABLE_PERMISSIONS_INCREASE;
          break;
        case Extension::DEPRECATED_DISABLE_RELOAD:
          new_value = Extension::DISABLE_RELOAD;
          break;
      }

      UpdateExtensionPref(*ext_id, kPrefDisableReasons,
                          new base::FundamentalValue(new_value));
      // Remove the old disable reason.
      UpdateExtensionPref(*ext_id, kDeprecatedPrefDisableReason, NULL);
    }
  }
}

PermissionSet* ExtensionPrefs::GetGrantedPermissions(
    const std::string& extension_id) {
  CHECK(Extension::IdIsValid(extension_id));
  return ReadPrefAsPermissionSet(extension_id, kPrefGrantedPermissions);
}

void ExtensionPrefs::AddGrantedPermissions(
    const std::string& extension_id,
    const PermissionSet* permissions) {
  CHECK(Extension::IdIsValid(extension_id));

  scoped_refptr<PermissionSet> granted_permissions(
      GetGrantedPermissions(extension_id));

  // The new granted permissions are the union of the already granted
  // permissions and the newly granted permissions.
  scoped_refptr<PermissionSet> new_perms(
      PermissionSet::CreateUnion(
          permissions, granted_permissions.get()));

  SetExtensionPrefPermissionSet(
      extension_id, kPrefGrantedPermissions, new_perms.get());
}

void ExtensionPrefs::RemoveGrantedPermissions(
    const std::string& extension_id,
    const PermissionSet* permissions) {
  CHECK(Extension::IdIsValid(extension_id));

  scoped_refptr<PermissionSet> granted_permissions(
      GetGrantedPermissions(extension_id));

  // The new granted permissions are the difference of the already granted
  // permissions and the newly ungranted permissions.
  scoped_refptr<PermissionSet> new_perms(
      PermissionSet::CreateDifference(
          granted_permissions.get(), permissions));

  SetExtensionPrefPermissionSet(
      extension_id, kPrefGrantedPermissions, new_perms.get());
}

PermissionSet* ExtensionPrefs::GetActivePermissions(
    const std::string& extension_id) {
  CHECK(Extension::IdIsValid(extension_id));
  return ReadPrefAsPermissionSet(extension_id, kPrefActivePermissions);
}

void ExtensionPrefs::SetActivePermissions(
    const std::string& extension_id,
    const PermissionSet* permissions) {
  SetExtensionPrefPermissionSet(
      extension_id, kPrefActivePermissions, permissions);
}

void ExtensionPrefs::SetExtensionRunning(const std::string& extension_id,
    bool is_running) {
  base::Value* value = new base::FundamentalValue(is_running);
  UpdateExtensionPref(extension_id, kPrefRunning, value);
}

bool ExtensionPrefs::IsExtensionRunning(const std::string& extension_id) {
  const base::DictionaryValue* extension = GetExtensionPref(extension_id);
  if (!extension)
    return false;
  bool running = false;
  extension->GetBoolean(kPrefRunning, &running);
  return running;
}

void ExtensionPrefs::SetIsActive(const std::string& extension_id,
                                 bool is_active) {
  base::Value* value = new base::FundamentalValue(is_active);
  UpdateExtensionPref(extension_id, kIsActive, value);
}

bool ExtensionPrefs::IsActive(const std::string& extension_id) {
  const base::DictionaryValue* extension = GetExtensionPref(extension_id);
  if (!extension)
    return false;
  bool is_active = false;
  extension->GetBoolean(kIsActive, &is_active);
  return is_active;
}

bool ExtensionPrefs::IsIncognitoEnabled(const std::string& extension_id) const {
  return ReadPrefAsBooleanAndReturn(extension_id, kPrefIncognitoEnabled);
}

void ExtensionPrefs::SetIsIncognitoEnabled(const std::string& extension_id,
                                           bool enabled) {
  UpdateExtensionPref(extension_id, kPrefIncognitoEnabled,
                      new base::FundamentalValue(enabled));
  extension_pref_value_map_->SetExtensionIncognitoState(extension_id, enabled);
}

bool ExtensionPrefs::AllowFileAccess(const std::string& extension_id) const {
  return ReadPrefAsBooleanAndReturn(extension_id, kPrefAllowFileAccess);
}

void ExtensionPrefs::SetAllowFileAccess(const std::string& extension_id,
                                        bool allow) {
  UpdateExtensionPref(extension_id, kPrefAllowFileAccess,
                      new base::FundamentalValue(allow));
}

bool ExtensionPrefs::HasAllowFileAccessSetting(
    const std::string& extension_id) const {
  const base::DictionaryValue* ext = GetExtensionPref(extension_id);
  return ext && ext->HasKey(kPrefAllowFileAccess);
}

bool ExtensionPrefs::DoesExtensionHaveState(
    const std::string& id, Extension::State check_state) const {
  const base::DictionaryValue* extension = GetExtensionPref(id);
  int state = -1;
  if (!extension || !extension->GetInteger(kPrefState, &state))
    return false;

  if (state < 0 || state >= Extension::NUM_STATES) {
    LOG(ERROR) << "Bad pref 'state' for extension '" << id << "'";
    return false;
  }

  return state == check_state;
}

bool ExtensionPrefs::IsExternalExtensionUninstalled(
    const std::string& id) const {
  return DoesExtensionHaveState(id, Extension::EXTERNAL_EXTENSION_UNINSTALLED);
}

bool ExtensionPrefs::IsExtensionDisabled(
    const std::string& id) const {
  return DoesExtensionHaveState(id, Extension::DISABLED);
}

ExtensionIdList ExtensionPrefs::GetToolbarOrder() {
  ExtensionIdList id_list_out;
  GetUserExtensionPrefIntoContainer(pref_names::kToolbar, &id_list_out);
  return id_list_out;
}

void ExtensionPrefs::SetToolbarOrder(const ExtensionIdList& extension_ids) {
  SetExtensionPrefFromContainer(pref_names::kToolbar, extension_ids);
}

bool ExtensionPrefs::GetKnownDisabled(ExtensionIdSet* id_set_out) {
  return GetUserExtensionPrefIntoContainer(pref_names::kKnownDisabled,
                                           id_set_out);
}

void ExtensionPrefs::SetKnownDisabled(const ExtensionIdSet& extension_ids) {
  SetExtensionPrefFromContainer(pref_names::kKnownDisabled, extension_ids);
}

void ExtensionPrefs::OnExtensionInstalled(
    const Extension* extension,
    Extension::State initial_state,
    bool blacklisted_for_malware,
    const syncer::StringOrdinal& page_ordinal,
    const std::string& install_parameter) {
  ScopedExtensionPrefUpdate update(prefs_, extension->id());
  base::DictionaryValue* extension_dict = update.Get();
  const base::Time install_time = time_provider_->GetCurrentTime();
  PopulateExtensionInfoPrefs(extension,
                             install_time,
                             initial_state,
                             blacklisted_for_malware,
                             install_parameter,
                             extension_dict);
  FinishExtensionInfoPrefs(extension->id(), install_time,
                           extension->RequiresSortOrdinal(),
                           page_ordinal, extension_dict);
}

void ExtensionPrefs::OnExtensionUninstalled(const std::string& extension_id,
                                            const Manifest::Location& location,
                                            bool external_uninstall) {
  app_sorting_->ClearOrdinals(extension_id);

  // For external extensions, we save a preference reminding ourself not to try
  // and install the extension anymore (except when |external_uninstall| is
  // true, which signifies that the registry key was deleted or the pref file
  // no longer lists the extension).
  if (!external_uninstall && Manifest::IsExternalLocation(location)) {
    UpdateExtensionPref(extension_id, kPrefState,
                        new base::FundamentalValue(
                            Extension::EXTERNAL_EXTENSION_UNINSTALLED));
    extension_pref_value_map_->SetExtensionState(extension_id, false);
    FOR_EACH_OBSERVER(ExtensionPrefsObserver,
                      observer_list_,
                      OnExtensionStateChanged(extension_id, false));
  } else {
    int creation_flags = GetCreationFlags(extension_id);
    if (creation_flags & Extension::IS_EPHEMERAL) {
      // Keep ephemeral apps around, but mark them as evicted.
      UpdateExtensionPref(extension_id, kPrefEvictedEphemeralApp,
                          new base::FundamentalValue(true));
    } else {
      DeleteExtensionPrefs(extension_id);
    }
  }
}

void ExtensionPrefs::SetExtensionState(const std::string& extension_id,
                                       Extension::State state) {
  UpdateExtensionPref(extension_id, kPrefState,
                      new base::FundamentalValue(state));
  bool enabled = (state == Extension::ENABLED);
  extension_pref_value_map_->SetExtensionState(extension_id, enabled);
  FOR_EACH_OBSERVER(ExtensionPrefsObserver,
                    observer_list_,
                    OnExtensionStateChanged(extension_id, enabled));
}

void ExtensionPrefs::SetExtensionBlacklistState(const std::string& extension_id,
                                                BlacklistState state) {
  SetExtensionBlacklisted(extension_id, state == BLACKLISTED_MALWARE);
  UpdateExtensionPref(extension_id, kPrefBlacklistState,
                      new base::FundamentalValue(state));
}

BlacklistState ExtensionPrefs::GetExtensionBlacklistState(
    const std::string& extension_id) {
  if (IsExtensionBlacklisted(extension_id))
    return BLACKLISTED_MALWARE;
  const base::DictionaryValue* ext_prefs = GetExtensionPref(extension_id);
  int int_value;
  if (ext_prefs && ext_prefs->GetInteger(kPrefBlacklistState, &int_value))
    return static_cast<BlacklistState>(int_value);

  return NOT_BLACKLISTED;
}

std::string ExtensionPrefs::GetVersionString(const std::string& extension_id) {
  const base::DictionaryValue* extension = GetExtensionPref(extension_id);
  if (!extension)
    return std::string();

  std::string version;
  extension->GetString(kPrefVersion, &version);

  return version;
}

void ExtensionPrefs::UpdateManifest(const Extension* extension) {
  if (!Manifest::IsUnpackedLocation(extension->location())) {
    const base::DictionaryValue* extension_dict =
        GetExtensionPref(extension->id());
    if (!extension_dict)
      return;
    const base::DictionaryValue* old_manifest = NULL;
    bool update_required =
        !extension_dict->GetDictionary(kPrefManifest, &old_manifest) ||
        !extension->manifest()->value()->Equals(old_manifest);
    if (update_required) {
      UpdateExtensionPref(extension->id(), kPrefManifest,
                          extension->manifest()->value()->DeepCopy());
    }
  }
}

base::FilePath ExtensionPrefs::GetExtensionPath(
    const std::string& extension_id) {
  const base::DictionaryValue* dict = GetExtensionPref(extension_id);
  if (!dict)
    return base::FilePath();

  std::string path;
  if (!dict->GetString(kPrefPath, &path))
    return base::FilePath();

  return install_directory_.Append(base::FilePath::FromUTF8Unsafe(path));
}

scoped_ptr<ExtensionInfo> ExtensionPrefs::GetInstalledInfoHelper(
    const std::string& extension_id,
    const base::DictionaryValue* extension) const {
  int location_value;
  if (!extension->GetInteger(kPrefLocation, &location_value))
    return scoped_ptr<ExtensionInfo>();

  base::FilePath::StringType path;
  if (!extension->GetString(kPrefPath, &path))
    return scoped_ptr<ExtensionInfo>();

  // Make path absolute. Unpacked extensions will already have absolute paths,
  // otherwise make it so.
  Manifest::Location location = static_cast<Manifest::Location>(location_value);
  if (!Manifest::IsUnpackedLocation(location)) {
    DCHECK(location == Manifest::COMPONENT ||
           !base::FilePath(path).IsAbsolute());
    path = install_directory_.Append(path).value();
  }

  // Only the following extension types have data saved in the preferences.
  if (location != Manifest::INTERNAL &&
      !Manifest::IsUnpackedLocation(location) &&
      !Manifest::IsExternalLocation(location)) {
    NOTREACHED();
    return scoped_ptr<ExtensionInfo>();
  }

  const base::DictionaryValue* manifest = NULL;
  if (!Manifest::IsUnpackedLocation(location) &&
      !extension->GetDictionary(kPrefManifest, &manifest)) {
    LOG(WARNING) << "Missing manifest for extension " << extension_id;
    // Just a warning for now.
  }

  return scoped_ptr<ExtensionInfo>(new ExtensionInfo(
      manifest, extension_id, base::FilePath(path), location));
}

scoped_ptr<ExtensionInfo> ExtensionPrefs::GetInstalledExtensionInfo(
    const std::string& extension_id) const {
  const base::DictionaryValue* ext = NULL;
  const base::DictionaryValue* extensions =
      prefs_->GetDictionary(pref_names::kExtensions);
  if (!extensions ||
      !extensions->GetDictionaryWithoutPathExpansion(extension_id, &ext))
    return scoped_ptr<ExtensionInfo>();
  int state_value;
  if (!ext->GetInteger(kPrefState, &state_value) ||
      state_value == Extension::ENABLED_COMPONENT) {
    // Old preferences files may not have kPrefState for component extensions.
    return scoped_ptr<ExtensionInfo>();
  }

  if (state_value == Extension::EXTERNAL_EXTENSION_UNINSTALLED) {
    LOG(WARNING) << "External extension with id " << extension_id
                 << " has been uninstalled by the user";
    return scoped_ptr<ExtensionInfo>();
  }

  if (IsEvictedEphemeralApp(ext)) {
    // Hide evicted ephemeral apps.
    return scoped_ptr<ExtensionInfo>();
  }

  return GetInstalledInfoHelper(extension_id, ext);
}

scoped_ptr<ExtensionPrefs::ExtensionsInfo>
ExtensionPrefs::GetInstalledExtensionsInfo() const {
  scoped_ptr<ExtensionsInfo> extensions_info(new ExtensionsInfo);

  const base::DictionaryValue* extensions =
      prefs_->GetDictionary(pref_names::kExtensions);
  for (base::DictionaryValue::Iterator extension_id(*extensions);
       !extension_id.IsAtEnd(); extension_id.Advance()) {
    if (!Extension::IdIsValid(extension_id.key()))
      continue;

    scoped_ptr<ExtensionInfo> info =
        GetInstalledExtensionInfo(extension_id.key());
    if (info)
      extensions_info->push_back(linked_ptr<ExtensionInfo>(info.release()));
  }

  return extensions_info.Pass();
}

scoped_ptr<ExtensionPrefs::ExtensionsInfo>
ExtensionPrefs::GetUninstalledExtensionsInfo() const {
  scoped_ptr<ExtensionsInfo> extensions_info(new ExtensionsInfo);

  const base::DictionaryValue* extensions =
      prefs_->GetDictionary(pref_names::kExtensions);
  for (base::DictionaryValue::Iterator extension_id(*extensions);
       !extension_id.IsAtEnd(); extension_id.Advance()) {
    const base::DictionaryValue* ext = NULL;
    if (!Extension::IdIsValid(extension_id.key()) ||
        !IsExternalExtensionUninstalled(extension_id.key()) ||
        !extension_id.value().GetAsDictionary(&ext))
      continue;

    scoped_ptr<ExtensionInfo> info =
        GetInstalledInfoHelper(extension_id.key(), ext);
    if (info)
      extensions_info->push_back(linked_ptr<ExtensionInfo>(info.release()));
  }

  return extensions_info.Pass();
}

void ExtensionPrefs::SetDelayedInstallInfo(
    const Extension* extension,
    Extension::State initial_state,
    bool blacklisted_for_malware,
    DelayReason delay_reason,
    const syncer::StringOrdinal& page_ordinal,
    const std::string& install_parameter) {
  base::DictionaryValue* extension_dict = new base::DictionaryValue();
  PopulateExtensionInfoPrefs(extension,
                             time_provider_->GetCurrentTime(),
                             initial_state,
                             blacklisted_for_malware,
                             install_parameter,
                             extension_dict);

  // Add transient data that is needed by FinishDelayedInstallInfo(), but
  // should not be in the final extension prefs. All entries here should have
  // a corresponding Remove() call in FinishDelayedInstallInfo().
  if (extension->RequiresSortOrdinal()) {
    extension_dict->SetString(
        kPrefSuggestedPageOrdinal,
        page_ordinal.IsValid() ? page_ordinal.ToInternalValue()
                               : std::string());
  }
  extension_dict->SetInteger(kDelayedInstallReason,
                             static_cast<int>(delay_reason));

  UpdateExtensionPref(extension->id(), kDelayedInstallInfo, extension_dict);
}

bool ExtensionPrefs::RemoveDelayedInstallInfo(
    const std::string& extension_id) {
  if (!GetExtensionPref(extension_id))
    return false;
  ScopedExtensionPrefUpdate update(prefs_, extension_id);
  bool result = update->Remove(kDelayedInstallInfo, NULL);
  return result;
}

bool ExtensionPrefs::FinishDelayedInstallInfo(
    const std::string& extension_id) {
  CHECK(Extension::IdIsValid(extension_id));
  ScopedExtensionPrefUpdate update(prefs_, extension_id);
  base::DictionaryValue* extension_dict = update.Get();
  base::DictionaryValue* pending_install_dict = NULL;
  if (!extension_dict->GetDictionary(kDelayedInstallInfo,
                                     &pending_install_dict)) {
    return false;
  }

  // Retrieve and clear transient values populated by SetDelayedInstallInfo().
  // Also do any other data cleanup that makes sense.
  std::string serialized_ordinal;
  syncer::StringOrdinal suggested_page_ordinal;
  bool needs_sort_ordinal = false;
  if (pending_install_dict->GetString(kPrefSuggestedPageOrdinal,
                                      &serialized_ordinal)) {
    suggested_page_ordinal = syncer::StringOrdinal(serialized_ordinal);
    needs_sort_ordinal = true;
    pending_install_dict->Remove(kPrefSuggestedPageOrdinal, NULL);
  }
  pending_install_dict->Remove(kDelayedInstallReason, NULL);

  const base::Time install_time = time_provider_->GetCurrentTime();
  pending_install_dict->Set(
      kPrefInstallTime,
      new base::StringValue(
          base::Int64ToString(install_time.ToInternalValue())));

  // Commit the delayed install data.
  for (base::DictionaryValue::Iterator it(*pending_install_dict); !it.IsAtEnd();
       it.Advance()) {
    extension_dict->Set(it.key(), it.value().DeepCopy());
  }
  FinishExtensionInfoPrefs(extension_id, install_time, needs_sort_ordinal,
                           suggested_page_ordinal, extension_dict);
  return true;
}

scoped_ptr<ExtensionInfo> ExtensionPrefs::GetDelayedInstallInfo(
    const std::string& extension_id) const {
  const base::DictionaryValue* extension_prefs =
      GetExtensionPref(extension_id);
  if (!extension_prefs)
    return scoped_ptr<ExtensionInfo>();

  const base::DictionaryValue* ext = NULL;
  if (!extension_prefs->GetDictionary(kDelayedInstallInfo, &ext))
    return scoped_ptr<ExtensionInfo>();

  return GetInstalledInfoHelper(extension_id, ext);
}

ExtensionPrefs::DelayReason ExtensionPrefs::GetDelayedInstallReason(
    const std::string& extension_id) const {
  const base::DictionaryValue* extension_prefs =
      GetExtensionPref(extension_id);
  if (!extension_prefs)
    return DELAY_REASON_NONE;

  const base::DictionaryValue* ext = NULL;
  if (!extension_prefs->GetDictionary(kDelayedInstallInfo, &ext))
    return DELAY_REASON_NONE;

  int delay_reason;
  if (!ext->GetInteger(kDelayedInstallReason, &delay_reason))
    return DELAY_REASON_NONE;

  return static_cast<DelayReason>(delay_reason);
}

scoped_ptr<ExtensionPrefs::ExtensionsInfo> ExtensionPrefs::
    GetAllDelayedInstallInfo() const {
  scoped_ptr<ExtensionsInfo> extensions_info(new ExtensionsInfo);

  const base::DictionaryValue* extensions =
      prefs_->GetDictionary(pref_names::kExtensions);
  for (base::DictionaryValue::Iterator extension_id(*extensions);
       !extension_id.IsAtEnd(); extension_id.Advance()) {
    if (!Extension::IdIsValid(extension_id.key()))
      continue;

    scoped_ptr<ExtensionInfo> info = GetDelayedInstallInfo(extension_id.key());
    if (info)
      extensions_info->push_back(linked_ptr<ExtensionInfo>(info.release()));
  }

  return extensions_info.Pass();
}

scoped_ptr<ExtensionPrefs::ExtensionsInfo>
ExtensionPrefs::GetEvictedEphemeralAppsInfo() const {
  scoped_ptr<ExtensionsInfo> extensions_info(new ExtensionsInfo);

  const base::DictionaryValue* extensions =
      prefs_->GetDictionary(pref_names::kExtensions);
  for (base::DictionaryValue::Iterator extension_id(*extensions);
       !extension_id.IsAtEnd(); extension_id.Advance()) {
    const base::DictionaryValue* ext = NULL;
    if (!Extension::IdIsValid(extension_id.key()) ||
        !extension_id.value().GetAsDictionary(&ext)) {
      continue;
    }

    if (!IsEvictedEphemeralApp(ext))
      continue;

    scoped_ptr<ExtensionInfo> info =
        GetInstalledInfoHelper(extension_id.key(), ext);
    if (info)
      extensions_info->push_back(linked_ptr<ExtensionInfo>(info.release()));
  }

  return extensions_info.Pass();
}

scoped_ptr<ExtensionInfo> ExtensionPrefs::GetEvictedEphemeralAppInfo(
    const std::string& extension_id) const {
  const base::DictionaryValue* extension_prefs = GetExtensionPref(extension_id);
  if (!extension_prefs)
    return scoped_ptr<ExtensionInfo>();

  if (!IsEvictedEphemeralApp(extension_prefs))
    return scoped_ptr<ExtensionInfo>();

  return GetInstalledInfoHelper(extension_id, extension_prefs);
}

void ExtensionPrefs::RemoveEvictedEphemeralApp(
    const std::string& extension_id) {
  bool evicted_ephemeral_app = false;
  if (ReadPrefAsBoolean(extension_id,
                        kPrefEvictedEphemeralApp,
                        &evicted_ephemeral_app) && evicted_ephemeral_app) {
    DeleteExtensionPrefs(extension_id);
  }
}

bool ExtensionPrefs::WasAppDraggedByUser(const std::string& extension_id) {
  return ReadPrefAsBooleanAndReturn(extension_id, kPrefUserDraggedApp);
}

void ExtensionPrefs::SetAppDraggedByUser(const std::string& extension_id) {
  UpdateExtensionPref(extension_id, kPrefUserDraggedApp,
                      new base::FundamentalValue(true));
}

bool ExtensionPrefs::IsFromWebStore(
    const std::string& extension_id) const {
  const base::DictionaryValue* dictionary = GetExtensionPref(extension_id);
  bool result = false;
  if (dictionary && dictionary->GetBoolean(kPrefFromWebStore, &result))
    return result;
  return false;
}

bool ExtensionPrefs::IsFromBookmark(
    const std::string& extension_id) const {
  const base::DictionaryValue* dictionary = GetExtensionPref(extension_id);
  bool result = false;
  if (dictionary && dictionary->GetBoolean(kPrefFromBookmark, &result))
    return result;
  return false;
}

int ExtensionPrefs::GetCreationFlags(const std::string& extension_id) const {
  int creation_flags = Extension::NO_FLAGS;
  if (!ReadPrefAsInteger(extension_id, kPrefCreationFlags, &creation_flags)) {
    // Since kPrefCreationFlags was added later, it will be missing for
    // previously installed extensions.
    if (IsFromBookmark(extension_id))
      creation_flags |= Extension::FROM_BOOKMARK;
    if (IsFromWebStore(extension_id))
      creation_flags |= Extension::FROM_WEBSTORE;
    if (WasInstalledByDefault(extension_id))
      creation_flags |= Extension::WAS_INSTALLED_BY_DEFAULT;
    if (WasInstalledByOem(extension_id))
      creation_flags |= Extension::WAS_INSTALLED_BY_OEM;
  }
  return creation_flags;
}

int ExtensionPrefs::GetDelayedInstallCreationFlags(
    const std::string& extension_id) const {
  int creation_flags = Extension::NO_FLAGS;
  const base::DictionaryValue* delayed_info = NULL;
  if (ReadPrefAsDictionary(extension_id, kDelayedInstallInfo, &delayed_info)) {
    delayed_info->GetInteger(kPrefCreationFlags, &creation_flags);
  }
  return creation_flags;
}

bool ExtensionPrefs::WasInstalledByDefault(
    const std::string& extension_id) const {
  const base::DictionaryValue* dictionary = GetExtensionPref(extension_id);
  bool result = false;
  if (dictionary &&
      dictionary->GetBoolean(kPrefWasInstalledByDefault, &result))
    return result;
  return false;
}

bool ExtensionPrefs::WasInstalledByOem(const std::string& extension_id) const {
  const base::DictionaryValue* dictionary = GetExtensionPref(extension_id);
  bool result = false;
  if (dictionary && dictionary->GetBoolean(kPrefWasInstalledByOem, &result))
    return result;
  return false;
}

base::Time ExtensionPrefs::GetInstallTime(
    const std::string& extension_id) const {
  const base::DictionaryValue* extension = GetExtensionPref(extension_id);
  if (!extension) {
    NOTREACHED();
    return base::Time();
  }
  std::string install_time_str;
  if (!extension->GetString(kPrefInstallTime, &install_time_str))
    return base::Time();
  int64 install_time_i64 = 0;
  if (!base::StringToInt64(install_time_str, &install_time_i64))
    return base::Time();
  return base::Time::FromInternalValue(install_time_i64);
}

base::Time ExtensionPrefs::GetLastLaunchTime(
    const std::string& extension_id) const {
  const base::DictionaryValue* extension = GetExtensionPref(extension_id);
  if (!extension)
    return base::Time();

  std::string launch_time_str;
  if (!extension->GetString(kPrefLastLaunchTime, &launch_time_str))
    return base::Time();
  int64 launch_time_i64 = 0;
  if (!base::StringToInt64(launch_time_str, &launch_time_i64))
    return base::Time();
  return base::Time::FromInternalValue(launch_time_i64);
}

void ExtensionPrefs::SetLastLaunchTime(const std::string& extension_id,
                                       const base::Time& time) {
  DCHECK(Extension::IdIsValid(extension_id));
  ScopedExtensionPrefUpdate update(prefs_, extension_id);
  SaveTime(update.Get(), kPrefLastLaunchTime, time);
}

void ExtensionPrefs::GetExtensions(ExtensionIdList* out) {
  CHECK(out);

  scoped_ptr<ExtensionsInfo> extensions_info(GetInstalledExtensionsInfo());

  for (size_t i = 0; i < extensions_info->size(); ++i) {
    ExtensionInfo* info = extensions_info->at(i).get();
    out->push_back(info->extension_id);
  }
}

// static
ExtensionIdList ExtensionPrefs::GetExtensionsFrom(
    const PrefService* pref_service) {
  ExtensionIdList result;

  const base::DictionaryValue* extension_prefs = NULL;
  const base::Value* extension_prefs_value =
      pref_service->GetUserPrefValue(pref_names::kExtensions);
  if (!extension_prefs_value ||
      !extension_prefs_value->GetAsDictionary(&extension_prefs)) {
    return result;  // Empty set
  }

  for (base::DictionaryValue::Iterator it(*extension_prefs); !it.IsAtEnd();
       it.Advance()) {
    const base::DictionaryValue* ext = NULL;
    if (!it.value().GetAsDictionary(&ext)) {
      NOTREACHED() << "Invalid pref for extension " << it.key();
      continue;
    }
    if (!IsBlacklistBitSet(ext))
      result.push_back(it.key());
  }
  return result;
}

void ExtensionPrefs::AddObserver(ExtensionPrefsObserver* observer) {
  observer_list_.AddObserver(observer);
}

void ExtensionPrefs::RemoveObserver(ExtensionPrefsObserver* observer) {
  observer_list_.RemoveObserver(observer);
}

void ExtensionPrefs::FixMissingPrefs(const ExtensionIdList& extension_ids) {
  // Fix old entries that did not get an installation time entry when they
  // were installed or don't have a preferences field.
  for (ExtensionIdList::const_iterator ext_id = extension_ids.begin();
       ext_id != extension_ids.end(); ++ext_id) {
    if (GetInstallTime(*ext_id) == base::Time()) {
      VLOG(1) << "Could not parse installation time of extension "
              << *ext_id << ". It was probably installed before setting "
              << kPrefInstallTime << " was introduced. Updating "
              << kPrefInstallTime << " to the current time.";
      const base::Time install_time = time_provider_->GetCurrentTime();
      UpdateExtensionPref(*ext_id,
                          kPrefInstallTime,
                          new base::StringValue(base::Int64ToString(
                              install_time.ToInternalValue())));
    }
  }
}

void ExtensionPrefs::InitPrefStore() {
  if (extensions_disabled_) {
    extension_pref_value_map_->NotifyInitializationCompleted();
    return;
  }

  // When this is called, the PrefService is initialized and provides access
  // to the user preferences stored in a JSON file.
  ExtensionIdList extension_ids;
  GetExtensions(&extension_ids);
  // Create empty preferences dictionary for each extension (these dictionaries
  // are pruned when persisting the preferences to disk).
  for (ExtensionIdList::iterator ext_id = extension_ids.begin();
       ext_id != extension_ids.end(); ++ext_id) {
    ScopedExtensionPrefUpdate update(prefs_, *ext_id);
    // This creates an empty dictionary if none is stored.
    update.Get();
  }

  FixMissingPrefs(extension_ids);
  MigratePermissions(extension_ids);
  MigrateDisableReasons(extension_ids);
  app_sorting_->Initialize(extension_ids);

  InitExtensionControlledPrefs(extension_pref_value_map_);

  extension_pref_value_map_->NotifyInitializationCompleted();
}

bool ExtensionPrefs::HasIncognitoPrefValue(const std::string& pref_key) {
  bool has_incognito_pref_value = false;
  extension_pref_value_map_->GetEffectivePrefValue(pref_key,
                                                   true,
                                                   &has_incognito_pref_value);
  return has_incognito_pref_value;
}

URLPatternSet ExtensionPrefs::GetAllowedInstallSites() {
  URLPatternSet result;
  const base::ListValue* list =
      prefs_->GetList(pref_names::kAllowedInstallSites);
  CHECK(list);

  for (size_t i = 0; i < list->GetSize(); ++i) {
    std::string entry_string;
    URLPattern entry(URLPattern::SCHEME_ALL);
    if (!list->GetString(i, &entry_string) ||
        entry.Parse(entry_string) != URLPattern::PARSE_SUCCESS) {
      LOG(ERROR) << "Invalid value for preference: "
                 << pref_names::kAllowedInstallSites << "." << i;
      continue;
    }
    result.AddPattern(entry);
  }

  return result;
}

const base::DictionaryValue* ExtensionPrefs::GetGeometryCache(
    const std::string& extension_id) const {
  const base::DictionaryValue* extension_prefs = GetExtensionPref(extension_id);
  if (!extension_prefs)
    return NULL;

  const base::DictionaryValue* ext = NULL;
  if (!extension_prefs->GetDictionary(kPrefGeometryCache, &ext))
    return NULL;

  return ext;
}

void ExtensionPrefs::SetGeometryCache(
    const std::string& extension_id,
    scoped_ptr<base::DictionaryValue> cache) {
  UpdateExtensionPref(extension_id, kPrefGeometryCache, cache.release());
}

const base::DictionaryValue* ExtensionPrefs::GetInstallSignature() {
  return prefs_->GetDictionary(kInstallSignature);
}

void ExtensionPrefs::SetInstallSignature(
    const base::DictionaryValue* signature) {
  if (signature) {
    prefs_->Set(kInstallSignature, *signature);
    DVLOG(1) << "SetInstallSignature - saving";
  } else {
    DVLOG(1) << "SetInstallSignature - clearing";
    prefs_->ClearPref(kInstallSignature);
  }
}

std::string ExtensionPrefs::GetInstallParam(
    const std::string& extension_id) const {
  const base::DictionaryValue* extension = GetExtensionPref(extension_id);
  if (!extension)  // Expected during unit testing.
    return std::string();
  std::string install_parameter;
  if (!extension->GetString(kPrefInstallParam, &install_parameter))
    return std::string();
  return install_parameter;
}

void ExtensionPrefs::SetInstallParam(const std::string& extension_id,
                                     const std::string& install_parameter) {
  UpdateExtensionPref(extension_id,
                      kPrefInstallParam,
                      new base::StringValue(install_parameter));
}

ExtensionPrefs::ExtensionPrefs(
    PrefService* prefs,
    const base::FilePath& root_dir,
    ExtensionPrefValueMap* extension_pref_value_map,
    scoped_ptr<AppSorting> app_sorting,
    scoped_ptr<TimeProvider> time_provider,
    bool extensions_disabled,
    const std::vector<ExtensionPrefsObserver*>& early_observers)
    : prefs_(prefs),
      install_directory_(root_dir),
      extension_pref_value_map_(extension_pref_value_map),
      app_sorting_(app_sorting.Pass()),
      time_provider_(time_provider.Pass()),
      extensions_disabled_(extensions_disabled) {
  app_sorting_->SetExtensionScopedPrefs(this);
  MakePathsRelative();

  // Ensure that any early observers are watching before prefs are initialized.
  for (std::vector<ExtensionPrefsObserver*>::const_iterator iter =
           early_observers.begin();
       iter != early_observers.end();
       ++iter) {
    AddObserver(*iter);
  }

  InitPrefStore();
}

void ExtensionPrefs::SetNeedsStorageGarbageCollection(bool value) {
  prefs_->SetBoolean(pref_names::kStorageGarbageCollect, value);
}

bool ExtensionPrefs::NeedsStorageGarbageCollection() {
  return prefs_->GetBoolean(pref_names::kStorageGarbageCollect);
}

// static
void ExtensionPrefs::RegisterProfilePrefs(
    user_prefs::PrefRegistrySyncable* registry) {
  registry->RegisterDictionaryPref(
      pref_names::kExtensions,
      user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
  registry->RegisterListPref(pref_names::kToolbar,
                             user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
  registry->RegisterIntegerPref(
      pref_names::kToolbarSize,
      -1,  // default value
      user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
  registry->RegisterDictionaryPref(
      kExtensionsBlacklistUpdate,
      user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
  registry->RegisterListPref(pref_names::kInstallAllowList,
                             user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
  registry->RegisterListPref(pref_names::kInstallDenyList,
                             user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
  registry->RegisterDictionaryPref(
      pref_names::kInstallForceList,
      user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
  registry->RegisterListPref(pref_names::kAllowedTypes,
                             user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
  registry->RegisterBooleanPref(
      pref_names::kStorageGarbageCollect,
      false,  // default value
      user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
  registry->RegisterInt64Pref(
      pref_names::kLastUpdateCheck,
      0,  // default value
      user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
  registry->RegisterInt64Pref(
      pref_names::kNextUpdateCheck,
      0,  // default value
      user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
  registry->RegisterListPref(pref_names::kAllowedInstallSites,
                             user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
  registry->RegisterStringPref(
      pref_names::kLastChromeVersion,
      std::string(),  // default value
      user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
  registry->RegisterListPref(pref_names::kKnownDisabled,
                             user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
#if defined(TOOLKIT_VIEWS)
  registry->RegisterIntegerPref(
      pref_names::kBrowserActionContainerWidth,
      0,
      user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
#endif
  registry->RegisterDictionaryPref(
      kInstallSignature,
      user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);

  registry->RegisterListPref(pref_names::kNativeMessagingBlacklist,
                             user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
  registry->RegisterListPref(pref_names::kNativeMessagingWhitelist,
                             user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
  registry->RegisterBooleanPref(
      pref_names::kNativeMessagingUserLevelHosts,
      true,  // default value
      user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
}

template <class ExtensionIdContainer>
bool ExtensionPrefs::GetUserExtensionPrefIntoContainer(
    const char* pref,
    ExtensionIdContainer* id_container_out) {
  DCHECK(id_container_out->empty());

  const base::Value* user_pref_value = prefs_->GetUserPrefValue(pref);
  const base::ListValue* user_pref_as_list;
  if (!user_pref_value || !user_pref_value->GetAsList(&user_pref_as_list))
    return false;

  std::insert_iterator<ExtensionIdContainer> insert_iterator(
      *id_container_out, id_container_out->end());
  std::string extension_id;
  for (base::ListValue::const_iterator value_it = user_pref_as_list->begin();
       value_it != user_pref_as_list->end(); ++value_it) {
    if (!(*value_it)->GetAsString(&extension_id)) {
      NOTREACHED();
      continue;
    }
    insert_iterator = extension_id;
  }
  return true;
}

template <class ExtensionIdContainer>
void ExtensionPrefs::SetExtensionPrefFromContainer(
    const char* pref,
    const ExtensionIdContainer& strings) {
  ListPrefUpdate update(prefs_, pref);
  base::ListValue* list_of_values = update.Get();
  list_of_values->Clear();
  for (typename ExtensionIdContainer::const_iterator iter = strings.begin();
       iter != strings.end(); ++iter) {
    list_of_values->Append(new base::StringValue(*iter));
  }
}

void ExtensionPrefs::PopulateExtensionInfoPrefs(
    const Extension* extension,
    const base::Time install_time,
    Extension::State initial_state,
    bool blacklisted_for_malware,
    const std::string& install_parameter,
    base::DictionaryValue* extension_dict) {
  // Leave the state blank for component extensions so that old chrome versions
  // loading new profiles do not fail in GetInstalledExtensionInfo. Older
  // Chrome versions would only check for an omitted state.
  if (initial_state != Extension::ENABLED_COMPONENT)
    extension_dict->Set(kPrefState, new base::FundamentalValue(initial_state));

  extension_dict->Set(kPrefLocation,
                      new base::FundamentalValue(extension->location()));
  extension_dict->Set(kPrefCreationFlags,
                      new base::FundamentalValue(extension->creation_flags()));
  extension_dict->Set(kPrefFromWebStore,
                      new base::FundamentalValue(extension->from_webstore()));
  extension_dict->Set(kPrefFromBookmark,
                      new base::FundamentalValue(extension->from_bookmark()));
  extension_dict->Set(
      kPrefWasInstalledByDefault,
      new base::FundamentalValue(extension->was_installed_by_default()));
  extension_dict->Set(
      kPrefWasInstalledByOem,
      new base::FundamentalValue(extension->was_installed_by_oem()));
  extension_dict->Set(kPrefInstallTime,
                      new base::StringValue(
                          base::Int64ToString(install_time.ToInternalValue())));
  if (blacklisted_for_malware)
    extension_dict->Set(kPrefBlacklist, new base::FundamentalValue(true));

  base::FilePath::StringType path = MakePathRelative(install_directory_,
                                                     extension->path());
  extension_dict->Set(kPrefPath, new base::StringValue(path));
  if (!install_parameter.empty()) {
    extension_dict->Set(kPrefInstallParam,
                        new base::StringValue(install_parameter));
  }
  // We store prefs about LOAD extensions, but don't cache their manifest
  // since it may change on disk.
  if (!Manifest::IsUnpackedLocation(extension->location())) {
    extension_dict->Set(kPrefManifest,
                        extension->manifest()->value()->DeepCopy());
  }
}

void ExtensionPrefs::InitExtensionControlledPrefs(
    ExtensionPrefValueMap* value_map) {
  ExtensionIdList extension_ids;
  GetExtensions(&extension_ids);

  for (ExtensionIdList::iterator extension_id = extension_ids.begin();
       extension_id != extension_ids.end();
       ++extension_id) {
    base::Time install_time = GetInstallTime(*extension_id);
    bool is_enabled = !IsExtensionDisabled(*extension_id);
    bool is_incognito_enabled = IsIncognitoEnabled(*extension_id);
    value_map->RegisterExtension(
        *extension_id, install_time, is_enabled, is_incognito_enabled);

    FOR_EACH_OBSERVER(
        ExtensionPrefsObserver,
        observer_list_,
        OnExtensionRegistered(*extension_id, install_time, is_enabled));

    // Set regular extension controlled prefs.
    LoadExtensionControlledPrefs(
        this, value_map, *extension_id, kExtensionPrefsScopeRegular);
    // Set incognito extension controlled prefs.
    LoadExtensionControlledPrefs(this,
                                 value_map,
                                 *extension_id,
                                 kExtensionPrefsScopeIncognitoPersistent);
    // Set regular-only extension controlled prefs.
    LoadExtensionControlledPrefs(
        this, value_map, *extension_id, kExtensionPrefsScopeRegularOnly);

    FOR_EACH_OBSERVER(ExtensionPrefsObserver,
                      observer_list_,
                      OnExtensionPrefsLoaded(*extension_id, this));
  }
}

void ExtensionPrefs::FinishExtensionInfoPrefs(
    const std::string& extension_id,
    const base::Time install_time,
    bool needs_sort_ordinal,
    const syncer::StringOrdinal& suggested_page_ordinal,
    base::DictionaryValue* extension_dict) {
  // Reinitializes various preferences with empty dictionaries.
  if (!extension_dict->HasKey(pref_names::kPrefPreferences)) {
    extension_dict->Set(pref_names::kPrefPreferences,
                        new base::DictionaryValue);
  }

  if (!extension_dict->HasKey(pref_names::kPrefIncognitoPreferences)) {
    extension_dict->Set(pref_names::kPrefIncognitoPreferences,
                        new base::DictionaryValue);
  }

  if (!extension_dict->HasKey(pref_names::kPrefRegularOnlyPreferences)) {
    extension_dict->Set(pref_names::kPrefRegularOnlyPreferences,
                        new base::DictionaryValue);
  }

  if (!extension_dict->HasKey(pref_names::kPrefContentSettings))
    extension_dict->Set(pref_names::kPrefContentSettings, new base::ListValue);

  if (!extension_dict->HasKey(pref_names::kPrefIncognitoContentSettings)) {
    extension_dict->Set(pref_names::kPrefIncognitoContentSettings,
                        new base::ListValue);
  }

  // If this point has been reached, any pending installs should be considered
  // out of date.
  extension_dict->Remove(kDelayedInstallInfo, NULL);

  // Clear state that may be registered from a previous install.
  extension_dict->Remove(EventRouter::kRegisteredEvents, NULL);

  // When evicted ephemeral apps are re-installed, this flag must be reset.
  extension_dict->Remove(kPrefEvictedEphemeralApp, NULL);

  // FYI, all code below here races on sudden shutdown because |extension_dict|,
  // |app_sorting_|, |extension_pref_value_map_|, and (potentially) observers
  // are updated non-transactionally. This is probably not fixable without
  // nested transactional updates to pref dictionaries.
  if (needs_sort_ordinal)
    app_sorting_->EnsureValidOrdinals(extension_id, suggested_page_ordinal);

  bool is_enabled = false;
  int initial_state;
  if (extension_dict->GetInteger(kPrefState, &initial_state)) {
    is_enabled = initial_state == Extension::ENABLED;
  }
  bool is_incognito_enabled = IsIncognitoEnabled(extension_id);

  extension_pref_value_map_->RegisterExtension(
      extension_id, install_time, is_enabled, is_incognito_enabled);

  FOR_EACH_OBSERVER(
      ExtensionPrefsObserver,
      observer_list_,
      OnExtensionRegistered(extension_id, install_time, is_enabled));
}

}  // namespace extensions