root/chrome/browser/metrics/metrics_service.cc

DEFINITIONS

1. IsSingleThreaded
2. ResponseCodeToStatus
3. GenerateLowEntropySource
4. MapCrashExitCodeForHistogram
5. MarkAppCleanShutdownAndCommit
6. SendSeparateInitialStabilityLog
7. OnDetailsAvailable
8. RegisterPrefs
9. DiscardOldStabilityStats
10. entropy_source_returned_
11. InitializeMetricsRecordingState
12. Start
13. StartRecordingForTests
14. Stop
15. EnableReporting
16. DisableReporting
17. GetClientId
18. CreateEntropyProvider
19. ForceClientIdCreation
20. EnableRecording
21. DisableRecording
22. recording_active
23. reporting_active
24. SetUpNotifications
25. BrowserChildProcessHostConnected
26. BrowserChildProcessCrashed
27. BrowserChildProcessInstanceCreated
28. Observe
29. HandleIdleSinceLastTransmission
30. RecordStartOfSessionEnd
31. RecordCompletedSessionEnd
32. OnAppEnterBackground
33. OnAppEnterForeground
34. LogNeedForCleanShutdown
35. SetExecutionPhase
36. RecordBreakpadRegistration
37. RecordBreakpadHasDebugger
38. CountBrowserCrashDumpAttempts
39. InitializeMetricsState
40. InitTaskGetHardwareClass
41. OnInitTaskGotHardwareClass
42. OnInitTaskGotPluginInfo
43. InitTaskGetGoogleUpdateData
44. OnInitTaskGotGoogleUpdateData
45. OnUserAction
46. ReceivedProfilerData
47. FinishedReceivingProfilerData
48. GetUptimes
49. ResetMetricsIDsIfNecessary
50. GetLowEntropySource
51. GenerateClientID
52. ScheduleNextStateSave
53. SaveLocalState
54. OpenNewLog
55. CloseCurrentLog
56. PushPendingLogsToPersistentStorage
57. StartSchedulerIfNecessary
58. StartScheduledUpload
59. StartFinalLogInfoCollection
60. OnMemoryDetailCollectionDone
61. OnHistogramSynchronizationDone
62. OnFinalLogInfoCollectionDone
63. StageNewLog
64. PrepareInitialStabilityLog
65. PrepareInitialMetricsLog
66. SendStagedLog
67. PrepareFetchWithStagedLog
68. OnURLFetchComplete
69. IncrementPrefValue
70. IncrementLongPrefsValue
71. LogLoadStarted
72. LogRendererCrash
73. LogRendererHang
74. UmaMetricsProperlyShutdown
75. RegisterSyntheticFieldTrial
76. CheckForClonedInstall
77. GetCurrentSyntheticFieldTrials
78. LogCleanShutdown
79. LogChromeOSCrash
80. LogPluginLoadingError
81. GetChildProcessStats
82. RecordPluginChanges
83. ShouldLogEvents
84. RecordBooleanPrefValue
85. RecordCurrentState
86. IsPluginProcess
87. StartExternalMetrics
88. IsMetricsReportingEnabled
89. IsCrashReportingEnabled

// 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.

//------------------------------------------------------------------------------
// Description of the life cycle of a instance of MetricsService.
//
//  OVERVIEW
//
// A MetricsService instance is typically created at application startup.  It is
// the central controller for the acquisition of log data, and the automatic
// transmission of that log data to an external server.  Its major job is to
// manage logs, grouping them for transmission, and transmitting them.  As part
// of its grouping, MS finalizes logs by including some just-in-time gathered
// memory statistics, snapshotting the current stats of numerous histograms,
// closing the logs, translating to protocol buffer format, and compressing the
// results for transmission.  Transmission includes submitting a compressed log
// as data in a URL-post, and retransmitting (or retaining at process
// termination) if the attempted transmission failed.  Retention across process
// terminations is done using the the PrefServices facilities. The retained logs
// (the ones that never got transmitted) are compressed and base64-encoded
// before being persisted.
//
// Logs fall into one of two categories: "initial logs," and "ongoing logs."
// There is at most one initial log sent for each complete run of Chrome (from
// startup, to browser shutdown).  An initial log is generally transmitted some
// short time (1 minute?) after startup, and includes stats such as recent crash
// info, the number and types of plugins, etc.  The external server's response
// to the initial log conceptually tells this MS if it should continue
// transmitting logs (during this session). The server response can actually be
// much more detailed, and always includes (at a minimum) how often additional
// ongoing logs should be sent.
//
// After the above initial log, a series of ongoing logs will be transmitted.
// The first ongoing log actually begins to accumulate information stating when
// the MS was first constructed.  Note that even though the initial log is
// commonly sent a full minute after startup, the initial log does not include
// much in the way of user stats.   The most common interlog period (delay)
// is 30 minutes. That time period starts when the first user action causes a
// logging event.  This means that if there is no user action, there may be long
// periods without any (ongoing) log transmissions.  Ongoing logs typically
// contain very detailed records of user activities (ex: opened tab, closed
// tab, fetched URL, maximized window, etc.)  In addition, just before an
// ongoing log is closed out, a call is made to gather memory statistics.  Those
// memory statistics are deposited into a histogram, and the log finalization
// code is then called.  In the finalization, a call to a Histogram server
// acquires a list of all local histograms that have been flagged for upload
// to the UMA server.  The finalization also acquires the most recent number
// of page loads, along with any counts of renderer or plugin crashes.
//
// When the browser shuts down, there will typically be a fragment of an ongoing
// log that has not yet been transmitted.  At shutdown time, that fragment is
// closed (including snapshotting histograms), and persisted, for potential
// transmission during a future run of the product.
//
// There are two slightly abnormal shutdown conditions.  There is a
// "disconnected scenario," and a "really fast startup and shutdown" scenario.
// In the "never connected" situation, the user has (during the running of the
// process) never established an internet connection.  As a result, attempts to
// transmit the initial log have failed, and a lot(?) of data has accumulated in
// the ongoing log (which didn't yet get closed, because there was never even a
// contemplation of sending it).  There is also a kindred "lost connection"
// situation, where a loss of connection prevented an ongoing log from being
// transmitted, and a (still open) log was stuck accumulating a lot(?) of data,
// while the earlier log retried its transmission.  In both of these
// disconnected situations, two logs need to be, and are, persistently stored
// for future transmission.
//
// The other unusual shutdown condition, termed "really fast startup and
// shutdown," involves the deliberate user termination of the process before
// the initial log is even formed or transmitted. In that situation, no logging
// is done, but the historical crash statistics remain (unlogged) for inclusion
// in a future run's initial log.  (i.e., we don't lose crash stats).
//
// With the above overview, we can now describe the state machine's various
// states, based on the State enum specified in the state_ member.  Those states
// are:
//
//  INITIALIZED,                   // Constructor was called.
//  INIT_TASK_SCHEDULED,           // Waiting for deferred init tasks to finish.
//  INIT_TASK_DONE,                // Waiting for timer to send initial log.
//  SENDING_INITIAL_STABILITY_LOG, // Initial stability log being sent.
//  SENDING_INITIAL_METRICS_LOG,   // Initial metrics log being sent.
//  SENDING_OLD_LOGS,              // Sending unsent logs from previous session.
//  SENDING_CURRENT_LOGS,          // Sending ongoing logs as they acrue.
//
// In more detail, we have:
//
//    INITIALIZED,            // Constructor was called.
// The MS has been constructed, but has taken no actions to compose the
// initial log.
//
//    INIT_TASK_SCHEDULED,    // Waiting for deferred init tasks to finish.
// Typically about 30 seconds after startup, a task is sent to a second thread
// (the file thread) to perform deferred (lower priority and slower)
// initialization steps such as getting the list of plugins.  That task will
// (when complete) make an async callback (via a Task) to indicate the
// completion.
//
//    INIT_TASK_DONE,         // Waiting for timer to send initial log.
// The callback has arrived, and it is now possible for an initial log to be
// created.  This callback typically arrives back less than one second after
// the deferred init task is dispatched.
//
//    SENDING_INITIAL_STABILITY_LOG,  // Initial stability log being sent.
// During initialization, if a crash occurred during the previous session, an
// initial stability log will be generated and registered with the log manager.
// This state will be entered if a stability log was prepared during metrics
// service initialization (in InitializeMetricsRecordingState()) and is waiting
// to be transmitted when it's time to send up the first log (per the reporting
// scheduler).  If there is no initial stability log (e.g. there was no previous
// crash), then this state will be skipped and the state will advance to
// SENDING_INITIAL_METRICS_LOG.
//
//    SENDING_INITIAL_METRICS_LOG,  // Initial metrics log being sent.
// This state is entered after the initial metrics log has been composed, and
// prepared for transmission.  This happens after SENDING_INITIAL_STABILITY_LOG
// if there was an initial stability log (see above).  It is also the case that
// any previously unsent logs have been loaded into instance variables for
// possible transmission.
//
//    SENDING_OLD_LOGS,       // Sending unsent logs from previous session.
// This state indicates that the initial log for this session has been
// successfully sent and it is now time to send any logs that were
// saved from previous sessions.  All such logs will be transmitted before
// exiting this state, and proceeding with ongoing logs from the current session
// (see next state).
//
//    SENDING_CURRENT_LOGS,   // Sending standard current logs as they accrue.
// Current logs are being accumulated.  Typically every 20 minutes a log is
// closed and finalized for transmission, at the same time as a new log is
// started.
//
// The progression through the above states is simple, and sequential, in the
// most common use cases.  States proceed from INITIAL to SENDING_CURRENT_LOGS,
// and remain in the latter until shutdown.
//
// The one unusual case is when the user asks that we stop logging.  When that
// happens, any staged (transmission in progress) log is persisted, and any log
// that is currently accumulating is also finalized and persisted.  We then
// regress back to the SEND_OLD_LOGS state in case the user enables log
// recording again during this session.  This way anything we have persisted
// will be sent automatically if/when we progress back to SENDING_CURRENT_LOG
// state.
//
// Another similar case is on mobile, when the application is backgrounded and
// then foregrounded again. Backgrounding created new "old" stored logs, so the
// state drops back from SENDING_CURRENT_LOGS to SENDING_OLD_LOGS so those logs
// will be sent.
//
// Also note that whenever we successfully send an old log, we mirror the list
// of logs into the PrefService. This ensures that IF we crash, we won't start
// up and retransmit our old logs again.
//
// Due to race conditions, it is always possible that a log file could be sent
// twice.  For example, if a log file is sent, but not yet acknowledged by
// the external server, and the user shuts down, then a copy of the log may be
// saved for re-transmission.  These duplicates could be filtered out server
// side, but are not expected to be a significant problem.
//
//
//------------------------------------------------------------------------------

#include "chrome/browser/metrics/metrics_service.h"

#include <algorithm>

#include "base/bind.h"
#include "base/callback.h"
#include "base/command_line.h"
#include "base/guid.h"
#include "base/md5.h"
#include "base/metrics/histogram.h"
#include "base/metrics/sparse_histogram.h"
#include "base/metrics/statistics_recorder.h"
#include "base/prefs/pref_registry_simple.h"
#include "base/prefs/pref_service.h"
#include "base/prefs/scoped_user_pref_update.h"
#include "base/rand_util.h"
#include "base/strings/string_number_conversions.h"
#include "base/strings/utf_string_conversions.h"
#include "base/threading/platform_thread.h"
#include "base/threading/thread.h"
#include "base/threading/thread_restrictions.h"
#include "base/tracked_objects.h"
#include "base/values.h"
#include "chrome/browser/browser_process.h"
#include "chrome/browser/chrome_notification_types.h"
#include "chrome/browser/io_thread.h"
#include "chrome/browser/memory_details.h"
#include "chrome/browser/metrics/cloned_install_detector.h"
#include "chrome/browser/metrics/compression_utils.h"
#include "chrome/browser/metrics/machine_id_provider.h"
#include "chrome/browser/metrics/metrics_log.h"
#include "chrome/browser/metrics/metrics_log_serializer.h"
#include "chrome/browser/metrics/metrics_reporting_scheduler.h"
#include "chrome/browser/metrics/time_ticks_experiment_win.h"
#include "chrome/browser/metrics/tracking_synchronizer.h"
#include "chrome/common/metrics/variations/variations_util.h"
#include "chrome/browser/net/http_pipelining_compatibility_client.h"
#include "chrome/browser/net/network_stats.h"
#include "chrome/browser/omnibox/omnibox_log.h"
#include "chrome/browser/ui/browser_list.h"
#include "chrome/browser/ui/browser_otr_state.h"
#include "chrome/browser/ui/search/search_tab_helper.h"
#include "chrome/common/chrome_constants.h"
#include "chrome/common/chrome_result_codes.h"
#include "chrome/common/chrome_switches.h"
#include "chrome/common/crash_keys.h"
#include "chrome/common/metrics/caching_permuted_entropy_provider.h"
#include "chrome/common/metrics/metrics_log_manager.h"
#include "chrome/common/net/test_server_locations.h"
#include "chrome/common/pref_names.h"
#include "chrome/common/render_messages.h"
#include "components/variations/entropy_provider.h"
#include "components/variations/metrics_util.h"
#include "content/public/browser/child_process_data.h"
#include "content/public/browser/histogram_fetcher.h"
#include "content/public/browser/load_notification_details.h"
#include "content/public/browser/notification_service.h"
#include "content/public/browser/plugin_service.h"
#include "content/public/browser/render_process_host.h"
#include "content/public/browser/user_metrics.h"
#include "content/public/browser/web_contents.h"
#include "content/public/common/process_type.h"
#include "content/public/common/webplugininfo.h"
#include "extensions/browser/process_map.h"
#include "net/base/load_flags.h"
#include "net/url_request/url_fetcher.h"

// TODO(port): port browser_distribution.h.
#if !defined(OS_POSIX)
#include "chrome/installer/util/browser_distribution.h"
#endif

#if defined(OS_CHROMEOS)
#include "chrome/browser/chromeos/external_metrics.h"
#include "chrome/browser/chromeos/settings/cros_settings.h"
#include "chromeos/system/statistics_provider.h"
#endif

#if defined(OS_WIN)
#include <windows.h>  // Needed for STATUS_* codes
#include "base/win/registry.h"
#endif

#if !defined(OS_ANDROID)
#include "chrome/browser/service_process/service_process_control.h"
#endif

using base::Time;
using content::BrowserThread;
using content::ChildProcessData;
using content::LoadNotificationDetails;
using content::PluginService;

namespace {

// Check to see that we're being called on only one thread.
bool IsSingleThreaded() {
  static base::PlatformThreadId thread_id = 0;
  if (!thread_id)
    thread_id = base::PlatformThread::CurrentId();
  return base::PlatformThread::CurrentId() == thread_id;
}

// The delay, in seconds, after starting recording before doing expensive
// initialization work.
#if defined(OS_ANDROID) || defined(OS_IOS)
// On mobile devices, a significant portion of sessions last less than a minute.
// Use a shorter timer on these platforms to avoid losing data.
// TODO(dfalcantara): To avoid delaying startup, tighten up initialization so
//                    that it occurs after the user gets their initial page.
const int kInitializationDelaySeconds = 5;
#else
const int kInitializationDelaySeconds = 30;
#endif

// This specifies the amount of time to wait for all renderers to send their
// data.
const int kMaxHistogramGatheringWaitDuration = 60000;  // 60 seconds.

// The maximum number of events in a log uploaded to the UMA server.
const int kEventLimit = 2400;

// If an upload fails, and the transmission was over this byte count, then we
// will discard the log, and not try to retransmit it.  We also don't persist
// the log to the prefs for transmission during the next chrome session if this
// limit is exceeded.
const size_t kUploadLogAvoidRetransmitSize = 50000;

// Interval, in minutes, between state saves.
const int kSaveStateIntervalMinutes = 5;

enum ResponseStatus {
  UNKNOWN_FAILURE,
  SUCCESS,
  BAD_REQUEST,  // Invalid syntax or log too large.
  NO_RESPONSE,
  NUM_RESPONSE_STATUSES
};

ResponseStatus ResponseCodeToStatus(int response_code) {
  switch (response_code) {
    case 200:
      return SUCCESS;
    case 400:
      return BAD_REQUEST;
    case net::URLFetcher::RESPONSE_CODE_INVALID:
      return NO_RESPONSE;
    default:
      return UNKNOWN_FAILURE;
  }
}

// The argument used to generate a non-identifying entropy source. We want no
// more than 13 bits of entropy, so use this max to return a number in the range
// [0, 7999] as the entropy source (12.97 bits of entropy).
const int kMaxLowEntropySize = 8000;

// Default prefs value for prefs::kMetricsLowEntropySource to indicate that the
// value has not yet been set.
const int kLowEntropySourceNotSet = -1;

// Generates a new non-identifying entropy source used to seed persistent
// activities.
int GenerateLowEntropySource() {
  return base::RandInt(0, kMaxLowEntropySize - 1);
}

// Converts an exit code into something that can be inserted into our
// histograms (which expect non-negative numbers less than MAX_INT).
int MapCrashExitCodeForHistogram(int exit_code) {
#if defined(OS_WIN)
  // Since |abs(STATUS_GUARD_PAGE_VIOLATION) == MAX_INT| it causes problems in
  // histograms.cc. Solve this by remapping it to a smaller value, which
  // hopefully doesn't conflict with other codes.
  if (exit_code == STATUS_GUARD_PAGE_VIOLATION)
    return 0x1FCF7EC3;  // Randomly picked number.
#endif

  return std::abs(exit_code);
}

void MarkAppCleanShutdownAndCommit() {
  PrefService* pref = g_browser_process->local_state();
  pref->SetBoolean(prefs::kStabilityExitedCleanly, true);
  pref->SetInteger(prefs::kStabilityExecutionPhase,
                   MetricsService::SHUTDOWN_COMPLETE);
  // Start writing right away (write happens on a different thread).
  pref->CommitPendingWrite();
}

// Returns whether initial stability metrics should be sent in a separate log.
bool SendSeparateInitialStabilityLog() {
  return base::FieldTrialList::FindFullName("UMAStability") == "SeparateLog";
}

}  // namespace


SyntheticTrialGroup::SyntheticTrialGroup(uint32 trial, uint32 group) {
  id.name = trial;
  id.group = group;
}

SyntheticTrialGroup::~SyntheticTrialGroup() {
}

// static
MetricsService::ShutdownCleanliness MetricsService::clean_shutdown_status_ =
    MetricsService::CLEANLY_SHUTDOWN;

MetricsService::ExecutionPhase MetricsService::execution_phase_ =
    MetricsService::UNINITIALIZED_PHASE;

// This is used to quickly log stats from child process related notifications in
// MetricsService::child_stats_buffer_.  The buffer's contents are transferred
// out when Local State is periodically saved.  The information is then
// reported to the UMA server on next launch.
struct MetricsService::ChildProcessStats {
 public:
  explicit ChildProcessStats(int process_type)
      : process_launches(0),
        process_crashes(0),
        instances(0),
        loading_errors(0),
        process_type(process_type) {}

  // This constructor is only used by the map to return some default value for
  // an index for which no value has been assigned.
  ChildProcessStats()
      : process_launches(0),
        process_crashes(0),
        instances(0),
        loading_errors(0),
        process_type(content::PROCESS_TYPE_UNKNOWN) {}

  // The number of times that the given child process has been launched
  int process_launches;

  // The number of times that the given child process has crashed
  int process_crashes;

  // The number of instances of this child process that have been created.
  // An instance is a DOM object rendered by this child process during a page
  // load.
  int instances;

  // The number of times there was an error loading an instance of this child
  // process.
  int loading_errors;

  int process_type;
};

// Handles asynchronous fetching of memory details.
// Will run the provided task after finished.
class MetricsMemoryDetails : public MemoryDetails {
 public:
  explicit MetricsMemoryDetails(const base::Closure& callback)
      : callback_(callback) {}

  virtual void OnDetailsAvailable() OVERRIDE {
    base::MessageLoop::current()->PostTask(FROM_HERE, callback_);
  }

 private:
  virtual ~MetricsMemoryDetails() {}

  base::Closure callback_;
  DISALLOW_COPY_AND_ASSIGN(MetricsMemoryDetails);
};

// static
void MetricsService::RegisterPrefs(PrefRegistrySimple* registry) {
  DCHECK(IsSingleThreaded());
  registry->RegisterBooleanPref(prefs::kMetricsResetIds, false);
  registry->RegisterStringPref(prefs::kMetricsClientID, std::string());
  registry->RegisterInt64Pref(prefs::kMetricsReportingEnabledTimestamp, 0);
  registry->RegisterIntegerPref(prefs::kMetricsLowEntropySource,
                                kLowEntropySourceNotSet);
  registry->RegisterInt64Pref(prefs::kStabilityLaunchTimeSec, 0);
  registry->RegisterInt64Pref(prefs::kStabilityLastTimestampSec, 0);
  registry->RegisterStringPref(prefs::kStabilityStatsVersion, std::string());
  registry->RegisterInt64Pref(prefs::kStabilityStatsBuildTime, 0);
  registry->RegisterBooleanPref(prefs::kStabilityExitedCleanly, true);
  registry->RegisterIntegerPref(prefs::kStabilityExecutionPhase,
                                UNINITIALIZED_PHASE);
  registry->RegisterBooleanPref(prefs::kStabilitySessionEndCompleted, true);
  registry->RegisterIntegerPref(prefs::kMetricsSessionID, -1);
  registry->RegisterIntegerPref(prefs::kStabilityLaunchCount, 0);
  registry->RegisterIntegerPref(prefs::kStabilityCrashCount, 0);
  registry->RegisterIntegerPref(prefs::kStabilityIncompleteSessionEndCount, 0);
  registry->RegisterIntegerPref(prefs::kStabilityPageLoadCount, 0);
  registry->RegisterIntegerPref(prefs::kStabilityRendererCrashCount, 0);
  registry->RegisterIntegerPref(prefs::kStabilityExtensionRendererCrashCount,
                                0);
  registry->RegisterIntegerPref(prefs::kStabilityRendererHangCount, 0);
  registry->RegisterIntegerPref(prefs::kStabilityChildProcessCrashCount, 0);
  registry->RegisterIntegerPref(prefs::kStabilityBreakpadRegistrationFail, 0);
  registry->RegisterIntegerPref(prefs::kStabilityBreakpadRegistrationSuccess,
                                0);
  registry->RegisterIntegerPref(prefs::kStabilityDebuggerPresent, 0);
  registry->RegisterIntegerPref(prefs::kStabilityDebuggerNotPresent, 0);
#if defined(OS_CHROMEOS)
  registry->RegisterIntegerPref(prefs::kStabilityOtherUserCrashCount, 0);
  registry->RegisterIntegerPref(prefs::kStabilityKernelCrashCount, 0);
  registry->RegisterIntegerPref(prefs::kStabilitySystemUncleanShutdownCount, 0);
#endif  // OS_CHROMEOS

  registry->RegisterStringPref(prefs::kStabilitySavedSystemProfile,
                               std::string());
  registry->RegisterStringPref(prefs::kStabilitySavedSystemProfileHash,
                               std::string());

  registry->RegisterListPref(prefs::kMetricsInitialLogs);
  registry->RegisterListPref(prefs::kMetricsOngoingLogs);

  registry->RegisterInt64Pref(prefs::kInstallDate, 0);
  registry->RegisterInt64Pref(prefs::kUninstallMetricsPageLoadCount, 0);
  registry->RegisterInt64Pref(prefs::kUninstallLaunchCount, 0);
  registry->RegisterInt64Pref(prefs::kUninstallMetricsUptimeSec, 0);
  registry->RegisterInt64Pref(prefs::kUninstallLastLaunchTimeSec, 0);
  registry->RegisterInt64Pref(prefs::kUninstallLastObservedRunTimeSec, 0);

  // TODO(asvitkine): Remove these once a couple of releases have passed.
  // http://crbug.com/357704
  registry->RegisterStringPref(prefs::kMetricsOldClientID, std::string());
  registry->RegisterIntegerPref(prefs::kMetricsOldLowEntropySource, 0);

#if defined(OS_ANDROID)
  RegisterPrefsAndroid(registry);
#endif  // defined(OS_ANDROID)
}

// static
void MetricsService::DiscardOldStabilityStats(PrefService* local_state) {
  local_state->SetBoolean(prefs::kStabilityExitedCleanly, true);
  local_state->SetInteger(prefs::kStabilityExecutionPhase, UNINITIALIZED_PHASE);
  local_state->SetBoolean(prefs::kStabilitySessionEndCompleted, true);

  local_state->SetInteger(prefs::kStabilityIncompleteSessionEndCount, 0);
  local_state->SetInteger(prefs::kStabilityBreakpadRegistrationSuccess, 0);
  local_state->SetInteger(prefs::kStabilityBreakpadRegistrationFail, 0);
  local_state->SetInteger(prefs::kStabilityDebuggerPresent, 0);
  local_state->SetInteger(prefs::kStabilityDebuggerNotPresent, 0);

  local_state->SetInteger(prefs::kStabilityLaunchCount, 0);
  local_state->SetInteger(prefs::kStabilityCrashCount, 0);

  local_state->SetInteger(prefs::kStabilityPageLoadCount, 0);
  local_state->SetInteger(prefs::kStabilityRendererCrashCount, 0);
  local_state->SetInteger(prefs::kStabilityRendererHangCount, 0);

  local_state->SetInt64(prefs::kStabilityLaunchTimeSec, 0);
  local_state->SetInt64(prefs::kStabilityLastTimestampSec, 0);

  local_state->ClearPref(prefs::kStabilityPluginStats);

  local_state->ClearPref(prefs::kMetricsInitialLogs);
  local_state->ClearPref(prefs::kMetricsOngoingLogs);

#if defined(OS_ANDROID)
  DiscardOldStabilityStatsAndroid(local_state);
#endif  // defined(OS_ANDROID)
}

MetricsService::MetricsService()
    : metrics_ids_reset_check_performed_(false),
      recording_active_(false),
      reporting_active_(false),
      test_mode_active_(false),
      state_(INITIALIZED),
      has_initial_stability_log_(false),
      low_entropy_source_(kLowEntropySourceNotSet),
      idle_since_last_transmission_(false),
      session_id_(-1),
      next_window_id_(0),
      self_ptr_factory_(this),
      state_saver_factory_(this),
      waiting_for_asynchronous_reporting_step_(false),
      num_async_histogram_fetches_in_progress_(0),
      entropy_source_returned_(LAST_ENTROPY_NONE) {
  DCHECK(IsSingleThreaded());

  log_manager_.set_log_serializer(new MetricsLogSerializer);
  log_manager_.set_max_ongoing_log_store_size(kUploadLogAvoidRetransmitSize);

  BrowserChildProcessObserver::Add(this);
}

MetricsService::~MetricsService() {
  DisableRecording();

  BrowserChildProcessObserver::Remove(this);
}

void MetricsService::InitializeMetricsRecordingState(
    ReportingState reporting_state) {
  InitializeMetricsState(reporting_state);

  base::Closure callback = base::Bind(&MetricsService::StartScheduledUpload,
                                      self_ptr_factory_.GetWeakPtr());
  scheduler_.reset(new MetricsReportingScheduler(callback));
}

void MetricsService::Start() {
  HandleIdleSinceLastTransmission(false);
  EnableRecording();
  EnableReporting();
}

void MetricsService::StartRecordingForTests() {
  test_mode_active_ = true;
  EnableRecording();
  DisableReporting();
}

void MetricsService::Stop() {
  HandleIdleSinceLastTransmission(false);
  DisableReporting();
  DisableRecording();
}

void MetricsService::EnableReporting() {
  if (reporting_active_)
    return;
  reporting_active_ = true;
  StartSchedulerIfNecessary();
}

void MetricsService::DisableReporting() {
  reporting_active_ = false;
}

std::string MetricsService::GetClientId() {
  return client_id_;
}

scoped_ptr<const base::FieldTrial::EntropyProvider>
MetricsService::CreateEntropyProvider(ReportingState reporting_state) {
  // For metrics reporting-enabled users, we combine the client ID and low
  // entropy source to get the final entropy source. Otherwise, only use the low
  // entropy source.
  // This has two useful properties:
  //  1) It makes the entropy source less identifiable for parties that do not
  //     know the low entropy source.
  //  2) It makes the final entropy source resettable.
  const int low_entropy_source_value = GetLowEntropySource();
  UMA_HISTOGRAM_SPARSE_SLOWLY("UMA.LowEntropySourceValue",
                              low_entropy_source_value);
  if (reporting_state == REPORTING_ENABLED) {
    if (entropy_source_returned_ == LAST_ENTROPY_NONE)
      entropy_source_returned_ = LAST_ENTROPY_HIGH;
    DCHECK_EQ(LAST_ENTROPY_HIGH, entropy_source_returned_);
    const std::string high_entropy_source =
        client_id_ + base::IntToString(low_entropy_source_value);
    return scoped_ptr<const base::FieldTrial::EntropyProvider>(
        new metrics::SHA1EntropyProvider(high_entropy_source));
  }

  if (entropy_source_returned_ == LAST_ENTROPY_NONE)
    entropy_source_returned_ = LAST_ENTROPY_LOW;
  DCHECK_EQ(LAST_ENTROPY_LOW, entropy_source_returned_);

#if defined(OS_ANDROID) || defined(OS_IOS)
  return scoped_ptr<const base::FieldTrial::EntropyProvider>(
      new metrics::CachingPermutedEntropyProvider(
          g_browser_process->local_state(),
          low_entropy_source_value,
          kMaxLowEntropySize));
#else
  return scoped_ptr<const base::FieldTrial::EntropyProvider>(
      new metrics::PermutedEntropyProvider(low_entropy_source_value,
                                           kMaxLowEntropySize));
#endif
}

void MetricsService::ForceClientIdCreation() {
  if (!client_id_.empty())
    return;

  ResetMetricsIDsIfNecessary();

  PrefService* pref = g_browser_process->local_state();
  client_id_ = pref->GetString(prefs::kMetricsClientID);
  if (!client_id_.empty())
    return;

  client_id_ = GenerateClientID();
  pref->SetString(prefs::kMetricsClientID, client_id_);

  if (pref->GetString(prefs::kMetricsOldClientID).empty()) {
    // Record the timestamp of when the user opted in to UMA.
    pref->SetInt64(prefs::kMetricsReportingEnabledTimestamp,
                   Time::Now().ToTimeT());
  } else {
    UMA_HISTOGRAM_BOOLEAN("UMA.ClientIdMigrated", true);
  }
  pref->ClearPref(prefs::kMetricsOldClientID);
}

void MetricsService::EnableRecording() {
  DCHECK(IsSingleThreaded());

  if (recording_active_)
    return;
  recording_active_ = true;

  ForceClientIdCreation();
  crash_keys::SetClientID(client_id_);
  if (!log_manager_.current_log())
    OpenNewLog();

  SetUpNotifications(&registrar_, this);
  base::RemoveActionCallback(action_callback_);
  action_callback_ = base::Bind(&MetricsService::OnUserAction,
                                base::Unretained(this));
  base::AddActionCallback(action_callback_);
}

void MetricsService::DisableRecording() {
  DCHECK(IsSingleThreaded());

  if (!recording_active_)
    return;
  recording_active_ = false;

  base::RemoveActionCallback(action_callback_);
  registrar_.RemoveAll();
  PushPendingLogsToPersistentStorage();
  DCHECK(!log_manager_.has_staged_log());
}

bool MetricsService::recording_active() const {
  DCHECK(IsSingleThreaded());
  return recording_active_;
}

bool MetricsService::reporting_active() const {
  DCHECK(IsSingleThreaded());
  return reporting_active_;
}

// static
void MetricsService::SetUpNotifications(
    content::NotificationRegistrar* registrar,
    content::NotificationObserver* observer) {
  registrar->Add(observer, chrome::NOTIFICATION_BROWSER_OPENED,
                 content::NotificationService::AllBrowserContextsAndSources());
  registrar->Add(observer, chrome::NOTIFICATION_BROWSER_CLOSED,
                 content::NotificationService::AllSources());
  registrar->Add(observer, chrome::NOTIFICATION_TAB_PARENTED,
                 content::NotificationService::AllSources());
  registrar->Add(observer, chrome::NOTIFICATION_TAB_CLOSING,
                 content::NotificationService::AllSources());
  registrar->Add(observer, content::NOTIFICATION_LOAD_START,
                 content::NotificationService::AllSources());
  registrar->Add(observer, content::NOTIFICATION_LOAD_STOP,
                 content::NotificationService::AllSources());
  registrar->Add(observer, content::NOTIFICATION_RENDERER_PROCESS_CLOSED,
                 content::NotificationService::AllSources());
  registrar->Add(observer, content::NOTIFICATION_RENDER_WIDGET_HOST_HANG,
                 content::NotificationService::AllSources());
  registrar->Add(observer, chrome::NOTIFICATION_OMNIBOX_OPENED_URL,
                 content::NotificationService::AllSources());
}

void MetricsService::BrowserChildProcessHostConnected(
    const content::ChildProcessData& data) {
  GetChildProcessStats(data).process_launches++;
}

void MetricsService::BrowserChildProcessCrashed(
    const content::ChildProcessData& data) {
  GetChildProcessStats(data).process_crashes++;
  // Exclude plugin crashes from the count below because we report them via
  // a separate UMA metric.
  if (!IsPluginProcess(data.process_type))
    IncrementPrefValue(prefs::kStabilityChildProcessCrashCount);
}

void MetricsService::BrowserChildProcessInstanceCreated(
    const content::ChildProcessData& data) {
  GetChildProcessStats(data).instances++;
}

void MetricsService::Observe(int type,
                             const content::NotificationSource& source,
                             const content::NotificationDetails& details) {
  DCHECK(log_manager_.current_log());
  DCHECK(IsSingleThreaded());

  // Check for notifications related to core stability metrics, or that are
  // just triggers to end idle mode. Anything else should be added in the later
  // switch statement, where they take effect only if general metrics should be
  // logged.
  bool handled = false;
  switch (type) {
    case chrome::NOTIFICATION_BROWSER_OPENED:
    case chrome::NOTIFICATION_BROWSER_CLOSED:
    case chrome::NOTIFICATION_TAB_PARENTED:
    case chrome::NOTIFICATION_TAB_CLOSING:
    case content::NOTIFICATION_LOAD_STOP:
      // These notifications are used only to break out of idle mode.
      handled = true;
      break;

    case content::NOTIFICATION_LOAD_START: {
      content::NavigationController* controller =
          content::Source<content::NavigationController>(source).ptr();
      content::WebContents* web_contents = controller->GetWebContents();
      LogLoadStarted(web_contents);
      handled = true;
      break;
    }

    case content::NOTIFICATION_RENDERER_PROCESS_CLOSED: {
      content::RenderProcessHost::RendererClosedDetails* process_details =
          content::Details<
              content::RenderProcessHost::RendererClosedDetails>(
                  details).ptr();
      content::RenderProcessHost* host =
          content::Source<content::RenderProcessHost>(source).ptr();
      LogRendererCrash(
          host, process_details->status, process_details->exit_code);
      handled = true;
      break;
    }

    case content::NOTIFICATION_RENDER_WIDGET_HOST_HANG:
      LogRendererHang();
      handled = true;
      break;

    default:
      // Everything else is handled after the early return check below.
      break;
  }

  // If it wasn't one of the stability-related notifications, and event
  // logging isn't suppressed, handle it.
  if (!handled && ShouldLogEvents()) {
    switch (type) {
      case chrome::NOTIFICATION_OMNIBOX_OPENED_URL: {
        MetricsLog* current_log =
            static_cast<MetricsLog*>(log_manager_.current_log());
        DCHECK(current_log);
        current_log->RecordOmniboxOpenedURL(
            *content::Details<OmniboxLog>(details).ptr());
        break;
      }

      default:
        NOTREACHED();
        break;
    }
  }

  HandleIdleSinceLastTransmission(false);
}

void MetricsService::HandleIdleSinceLastTransmission(bool in_idle) {
  // If there wasn't a lot of action, maybe the computer was asleep, in which
  // case, the log transmissions should have stopped.  Here we start them up
  // again.
  if (!in_idle && idle_since_last_transmission_)
    StartSchedulerIfNecessary();
  idle_since_last_transmission_ = in_idle;
}

void MetricsService::RecordStartOfSessionEnd() {
  LogCleanShutdown();
  RecordBooleanPrefValue(prefs::kStabilitySessionEndCompleted, false);
}

void MetricsService::RecordCompletedSessionEnd() {
  LogCleanShutdown();
  RecordBooleanPrefValue(prefs::kStabilitySessionEndCompleted, true);
}

#if defined(OS_ANDROID) || defined(OS_IOS)
void MetricsService::OnAppEnterBackground() {
  scheduler_->Stop();

  MarkAppCleanShutdownAndCommit();

  // At this point, there's no way of knowing when the process will be
  // killed, so this has to be treated similar to a shutdown, closing and
  // persisting all logs. Unlinke a shutdown, the state is primed to be ready
  // to continue logging and uploading if the process does return.
  if (recording_active() && state_ >= SENDING_INITIAL_STABILITY_LOG) {
    PushPendingLogsToPersistentStorage();
    // Persisting logs closes the current log, so start recording a new log
    // immediately to capture any background work that might be done before the
    // process is killed.
    OpenNewLog();
  }
}

void MetricsService::OnAppEnterForeground() {
  PrefService* pref = g_browser_process->local_state();
  pref->SetBoolean(prefs::kStabilityExitedCleanly, false);

  StartSchedulerIfNecessary();
}
#else
void MetricsService::LogNeedForCleanShutdown() {
  PrefService* pref = g_browser_process->local_state();
  pref->SetBoolean(prefs::kStabilityExitedCleanly, false);
  // Redundant setting to be sure we call for a clean shutdown.
  clean_shutdown_status_ = NEED_TO_SHUTDOWN;
}
#endif  // defined(OS_ANDROID) || defined(OS_IOS)

// static
void MetricsService::SetExecutionPhase(ExecutionPhase execution_phase) {
  execution_phase_ = execution_phase;
  PrefService* pref = g_browser_process->local_state();
  pref->SetInteger(prefs::kStabilityExecutionPhase, execution_phase_);
}

void MetricsService::RecordBreakpadRegistration(bool success) {
  if (!success)
    IncrementPrefValue(prefs::kStabilityBreakpadRegistrationFail);
  else
    IncrementPrefValue(prefs::kStabilityBreakpadRegistrationSuccess);
}

void MetricsService::RecordBreakpadHasDebugger(bool has_debugger) {
  if (!has_debugger)
    IncrementPrefValue(prefs::kStabilityDebuggerNotPresent);
  else
    IncrementPrefValue(prefs::kStabilityDebuggerPresent);
}

#if defined(OS_WIN)
void MetricsService::CountBrowserCrashDumpAttempts() {
  // Open the registry key for iteration.
  base::win::RegKey regkey;
  if (regkey.Open(HKEY_CURRENT_USER,
                  chrome::kBrowserCrashDumpAttemptsRegistryPath,
                  KEY_ALL_ACCESS) != ERROR_SUCCESS) {
    return;
  }

  // The values we're interested in counting are all prefixed with the version.
  base::string16 chrome_version(base::ASCIIToUTF16(chrome::kChromeVersion));

  // Track a list of values to delete. We don't modify the registry key while
  // we're iterating over its values.
  typedef std::vector<base::string16> StringVector;
  StringVector to_delete;

  // Iterate over the values in the key counting dumps with and without crashes.
  // We directly walk the values instead of using RegistryValueIterator in order
  // to read all of the values as DWORDS instead of strings.
  base::string16 name;
  DWORD value = 0;
  int dumps_with_crash = 0;
  int dumps_with_no_crash = 0;
  for (int i = regkey.GetValueCount() - 1; i >= 0; --i) {
    if (regkey.GetValueNameAt(i, &name) == ERROR_SUCCESS &&
        StartsWith(name, chrome_version, false) &&
        regkey.ReadValueDW(name.c_str(), &value) == ERROR_SUCCESS) {
      to_delete.push_back(name);
      if (value == 0)
        ++dumps_with_no_crash;
      else
        ++dumps_with_crash;
    }
  }

  // Delete the registry keys we've just counted.
  for (StringVector::iterator i = to_delete.begin(); i != to_delete.end(); ++i)
    regkey.DeleteValue(i->c_str());

  // Capture the histogram samples.
  if (dumps_with_crash != 0)
    UMA_HISTOGRAM_COUNTS("Chrome.BrowserDumpsWithCrash", dumps_with_crash);
  if (dumps_with_no_crash != 0)
    UMA_HISTOGRAM_COUNTS("Chrome.BrowserDumpsWithNoCrash", dumps_with_no_crash);
  int total_dumps = dumps_with_crash + dumps_with_no_crash;
  if (total_dumps != 0)
    UMA_HISTOGRAM_COUNTS("Chrome.BrowserCrashDumpAttempts", total_dumps);
}
#endif  // defined(OS_WIN)

//------------------------------------------------------------------------------
// private methods
//------------------------------------------------------------------------------


//------------------------------------------------------------------------------
// Initialization methods

void MetricsService::InitializeMetricsState(ReportingState reporting_state) {
#if defined(OS_POSIX)
  network_stats_server_ = chrome_common_net::kEchoTestServerLocation;
  http_pipelining_test_server_ = chrome_common_net::kPipelineTestServerBaseUrl;
#else
  BrowserDistribution* dist = BrowserDistribution::GetDistribution();
  network_stats_server_ = dist->GetNetworkStatsServer();
  http_pipelining_test_server_ = dist->GetHttpPipeliningTestServer();
#endif

  PrefService* pref = g_browser_process->local_state();
  DCHECK(pref);

  // TODO(asvitkine): Kill this logic when SendSeparateInitialStabilityLog() is
  // is made the default behavior.
  if ((pref->GetInt64(prefs::kStabilityStatsBuildTime)
       != MetricsLog::GetBuildTime()) ||
      (pref->GetString(prefs::kStabilityStatsVersion)
       != MetricsLog::GetVersionString())) {
    // This is a new version, so we don't want to confuse the stats about the
    // old version with info that we upload.
    DiscardOldStabilityStats(pref);
    pref->SetString(prefs::kStabilityStatsVersion,
                    MetricsLog::GetVersionString());
    pref->SetInt64(prefs::kStabilityStatsBuildTime,
                   MetricsLog::GetBuildTime());
  }

  session_id_ = pref->GetInteger(prefs::kMetricsSessionID);

#if defined(OS_ANDROID)
  LogAndroidStabilityToPrefs(pref);
#endif  // defined(OS_ANDROID)

  if (!pref->GetBoolean(prefs::kStabilityExitedCleanly)) {
    IncrementPrefValue(prefs::kStabilityCrashCount);
    // Reset flag, and wait until we call LogNeedForCleanShutdown() before
    // monitoring.
    pref->SetBoolean(prefs::kStabilityExitedCleanly, true);

    // TODO(rtenneti): On windows, consider saving/getting execution_phase from
    // the registry.
    int execution_phase = pref->GetInteger(prefs::kStabilityExecutionPhase);
    UMA_HISTOGRAM_SPARSE_SLOWLY("Chrome.Browser.CrashedExecutionPhase",
                                execution_phase);

    // If the previous session didn't exit cleanly, then prepare an initial
    // stability log if UMA is enabled.
    bool reporting_will_be_enabled = (reporting_state == REPORTING_ENABLED);
    if (reporting_will_be_enabled && SendSeparateInitialStabilityLog())
      PrepareInitialStabilityLog();
  }

  // Update session ID.
  ++session_id_;
  pref->SetInteger(prefs::kMetricsSessionID, session_id_);

  // Stability bookkeeping
  IncrementPrefValue(prefs::kStabilityLaunchCount);

  DCHECK_EQ(UNINITIALIZED_PHASE, execution_phase_);
  SetExecutionPhase(START_METRICS_RECORDING);

#if defined(OS_WIN)
  CountBrowserCrashDumpAttempts();
#endif  // defined(OS_WIN)

  if (!pref->GetBoolean(prefs::kStabilitySessionEndCompleted)) {
    IncrementPrefValue(prefs::kStabilityIncompleteSessionEndCount);
    // This is marked false when we get a WM_ENDSESSION.
    pref->SetBoolean(prefs::kStabilitySessionEndCompleted, true);
  }

  // Call GetUptimes() for the first time, thus allowing all later calls
  // to record incremental uptimes accurately.
  base::TimeDelta ignored_uptime_parameter;
  base::TimeDelta startup_uptime;
  GetUptimes(pref, &startup_uptime, &ignored_uptime_parameter);
  DCHECK_EQ(0, startup_uptime.InMicroseconds());
  // For backwards compatibility, leave this intact in case Omaha is checking
  // them.  prefs::kStabilityLastTimestampSec may also be useless now.
  // TODO(jar): Delete these if they have no uses.
  pref->SetInt64(prefs::kStabilityLaunchTimeSec, Time::Now().ToTimeT());

  // Bookkeeping for the uninstall metrics.
  IncrementLongPrefsValue(prefs::kUninstallLaunchCount);

  // Get stats on use of command line.
  const CommandLine* command_line(CommandLine::ForCurrentProcess());
  size_t common_commands = 0;
  if (command_line->HasSwitch(switches::kUserDataDir)) {
    ++common_commands;
    UMA_HISTOGRAM_COUNTS_100("Chrome.CommandLineDatDirCount", 1);
  }

  if (command_line->HasSwitch(switches::kApp)) {
    ++common_commands;
    UMA_HISTOGRAM_COUNTS_100("Chrome.CommandLineAppModeCount", 1);
  }

  size_t switch_count = command_line->GetSwitches().size();
  UMA_HISTOGRAM_COUNTS_100("Chrome.CommandLineFlagCount", switch_count);
  UMA_HISTOGRAM_COUNTS_100("Chrome.CommandLineUncommonFlagCount",
                           switch_count - common_commands);

  // Kick off the process of saving the state (so the uptime numbers keep
  // getting updated) every n minutes.
  ScheduleNextStateSave();
}

// static
void MetricsService::InitTaskGetHardwareClass(
    base::WeakPtr<MetricsService> self,
    base::MessageLoopProxy* target_loop) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));

  std::string hardware_class;
#if defined(OS_CHROMEOS)
  chromeos::system::StatisticsProvider::GetInstance()->GetMachineStatistic(
      "hardware_class", &hardware_class);
#endif  // OS_CHROMEOS

  target_loop->PostTask(FROM_HERE,
      base::Bind(&MetricsService::OnInitTaskGotHardwareClass,
          self, hardware_class));
}

void MetricsService::OnInitTaskGotHardwareClass(
    const std::string& hardware_class) {
  DCHECK_EQ(INIT_TASK_SCHEDULED, state_);
  hardware_class_ = hardware_class;

#if defined(ENABLE_PLUGINS)
  // Start the next part of the init task: loading plugin information.
  PluginService::GetInstance()->GetPlugins(
      base::Bind(&MetricsService::OnInitTaskGotPluginInfo,
          self_ptr_factory_.GetWeakPtr()));
#else
  std::vector<content::WebPluginInfo> plugin_list_empty;
  OnInitTaskGotPluginInfo(plugin_list_empty);
#endif  // defined(ENABLE_PLUGINS)
}

void MetricsService::OnInitTaskGotPluginInfo(
    const std::vector<content::WebPluginInfo>& plugins) {
  DCHECK_EQ(INIT_TASK_SCHEDULED, state_);
  plugins_ = plugins;

  // Schedules a task on a blocking pool thread to gather Google Update
  // statistics (requires Registry reads).
  BrowserThread::PostBlockingPoolTask(
      FROM_HERE,
      base::Bind(&MetricsService::InitTaskGetGoogleUpdateData,
                 self_ptr_factory_.GetWeakPtr(),
                 base::MessageLoop::current()->message_loop_proxy()));
}

// static
void MetricsService::InitTaskGetGoogleUpdateData(
    base::WeakPtr<MetricsService> self,
    base::MessageLoopProxy* target_loop) {
  GoogleUpdateMetrics google_update_metrics;

#if defined(OS_WIN) && defined(GOOGLE_CHROME_BUILD)
  const bool system_install = GoogleUpdateSettings::IsSystemInstall();

  google_update_metrics.is_system_install = system_install;
  google_update_metrics.last_started_au =
      GoogleUpdateSettings::GetGoogleUpdateLastStartedAU(system_install);
  google_update_metrics.last_checked =
      GoogleUpdateSettings::GetGoogleUpdateLastChecked(system_install);
  GoogleUpdateSettings::GetUpdateDetailForGoogleUpdate(
      system_install,
      &google_update_metrics.google_update_data);
  GoogleUpdateSettings::GetUpdateDetail(
      system_install,
      &google_update_metrics.product_data);
#endif  // defined(OS_WIN) && defined(GOOGLE_CHROME_BUILD)

  target_loop->PostTask(FROM_HERE,
      base::Bind(&MetricsService::OnInitTaskGotGoogleUpdateData,
          self, google_update_metrics));
}

void MetricsService::OnInitTaskGotGoogleUpdateData(
    const GoogleUpdateMetrics& google_update_metrics) {
  DCHECK_EQ(INIT_TASK_SCHEDULED, state_);

  google_update_metrics_ = google_update_metrics;

  // Start the next part of the init task: fetching performance data.  This will
  // call into |FinishedReceivingProfilerData()| when the task completes.
  chrome_browser_metrics::TrackingSynchronizer::FetchProfilerDataAsynchronously(
      self_ptr_factory_.GetWeakPtr());
}

void MetricsService::OnUserAction(const std::string& action) {
  if (!ShouldLogEvents())
    return;

  log_manager_.current_log()->RecordUserAction(action.c_str());
  HandleIdleSinceLastTransmission(false);
}

void MetricsService::ReceivedProfilerData(
    const tracked_objects::ProcessDataSnapshot& process_data,
    int process_type) {
  DCHECK_EQ(INIT_TASK_SCHEDULED, state_);

  // Upon the first callback, create the initial log so that we can immediately
  // save the profiler data.
  if (!initial_metrics_log_.get())
    initial_metrics_log_.reset(new MetricsLog(client_id_, session_id_));

  initial_metrics_log_->RecordProfilerData(process_data, process_type);
}

void MetricsService::FinishedReceivingProfilerData() {
  DCHECK_EQ(INIT_TASK_SCHEDULED, state_);
  state_ = INIT_TASK_DONE;
  scheduler_->InitTaskComplete();
}

void MetricsService::GetUptimes(PrefService* pref,
                                base::TimeDelta* incremental_uptime,
                                base::TimeDelta* uptime) {
  base::TimeTicks now = base::TimeTicks::Now();
  // If this is the first call, init |first_updated_time_| and
  // |last_updated_time_|.
  if (last_updated_time_.is_null()) {
    first_updated_time_ = now;
    last_updated_time_ = now;
  }
  *incremental_uptime = now - last_updated_time_;
  *uptime = now - first_updated_time_;
  last_updated_time_ = now;

  const int64 incremental_time_secs = incremental_uptime->InSeconds();
  if (incremental_time_secs > 0) {
    int64 metrics_uptime = pref->GetInt64(prefs::kUninstallMetricsUptimeSec);
    metrics_uptime += incremental_time_secs;
    pref->SetInt64(prefs::kUninstallMetricsUptimeSec, metrics_uptime);
  }
}

void MetricsService::ResetMetricsIDsIfNecessary() {
  if (metrics_ids_reset_check_performed_)
    return;

  metrics_ids_reset_check_performed_ = true;

  PrefService* local_state = g_browser_process->local_state();
  if (!local_state->GetBoolean(prefs::kMetricsResetIds))
    return;

  UMA_HISTOGRAM_BOOLEAN("UMA.MetricsIDsReset", true);

  DCHECK(client_id_.empty());
  DCHECK_EQ(kLowEntropySourceNotSet, low_entropy_source_);

  local_state->ClearPref(prefs::kMetricsClientID);
  local_state->ClearPref(prefs::kMetricsLowEntropySource);
  local_state->ClearPref(prefs::kMetricsResetIds);
}

int MetricsService::GetLowEntropySource() {
  // Note that the default value for the low entropy source and the default pref
  // value are both kLowEntropySourceNotSet, which is used to identify if the
  // value has been set or not.
  if (low_entropy_source_ != kLowEntropySourceNotSet)
    return low_entropy_source_;

  ResetMetricsIDsIfNecessary();

  PrefService* local_state = g_browser_process->local_state();
  const CommandLine* command_line(CommandLine::ForCurrentProcess());
  // Only try to load the value from prefs if the user did not request a reset.
  // Otherwise, skip to generating a new value.
  if (!command_line->HasSwitch(switches::kResetVariationState)) {
    int value = local_state->GetInteger(prefs::kMetricsLowEntropySource);
    // If the value is outside the [0, kMaxLowEntropySize) range, re-generate
    // it below.
    if (value >= 0 && value < kMaxLowEntropySize) {
      low_entropy_source_ = value;
      UMA_HISTOGRAM_BOOLEAN("UMA.GeneratedLowEntropySource", false);
      return low_entropy_source_;
    }
  }

  UMA_HISTOGRAM_BOOLEAN("UMA.GeneratedLowEntropySource", true);
  low_entropy_source_ = GenerateLowEntropySource();
  local_state->SetInteger(prefs::kMetricsLowEntropySource, low_entropy_source_);
  local_state->ClearPref(prefs::kMetricsOldLowEntropySource);
  metrics::CachingPermutedEntropyProvider::ClearCache(local_state);

  return low_entropy_source_;
}

// static
std::string MetricsService::GenerateClientID() {
  return base::GenerateGUID();
}

//------------------------------------------------------------------------------
// State save methods

void MetricsService::ScheduleNextStateSave() {
  state_saver_factory_.InvalidateWeakPtrs();

  base::MessageLoop::current()->PostDelayedTask(FROM_HERE,
      base::Bind(&MetricsService::SaveLocalState,
                 state_saver_factory_.GetWeakPtr()),
      base::TimeDelta::FromMinutes(kSaveStateIntervalMinutes));
}

void MetricsService::SaveLocalState() {
  PrefService* pref = g_browser_process->local_state();
  if (!pref) {
    NOTREACHED();
    return;
  }

  RecordCurrentState(pref);

  // TODO(jar):110021 Does this run down the batteries????
  ScheduleNextStateSave();
}


//------------------------------------------------------------------------------
// Recording control methods

void MetricsService::OpenNewLog() {
  DCHECK(!log_manager_.current_log());

  log_manager_.BeginLoggingWithLog(new MetricsLog(client_id_, session_id_),
                                   MetricsLog::ONGOING_LOG);
  if (state_ == INITIALIZED) {
    // We only need to schedule that run once.
    state_ = INIT_TASK_SCHEDULED;

    // Schedules a task on the file thread for execution of slower
    // initialization steps (such as plugin list generation) necessary
    // for sending the initial log.  This avoids blocking the main UI
    // thread.
    BrowserThread::PostDelayedTask(
        BrowserThread::FILE,
        FROM_HERE,
        base::Bind(&MetricsService::InitTaskGetHardwareClass,
            self_ptr_factory_.GetWeakPtr(),
            base::MessageLoop::current()->message_loop_proxy()),
        base::TimeDelta::FromSeconds(kInitializationDelaySeconds));
  }
}

void MetricsService::CloseCurrentLog() {
  if (!log_manager_.current_log())
    return;

  // TODO(jar): Integrate bounds on log recording more consistently, so that we
  // can stop recording logs that are too big much sooner.
  if (log_manager_.current_log()->num_events() > kEventLimit) {
    UMA_HISTOGRAM_COUNTS("UMA.Discarded Log Events",
                         log_manager_.current_log()->num_events());
    log_manager_.DiscardCurrentLog();
    OpenNewLog();  // Start trivial log to hold our histograms.
  }

  // Adds to ongoing logs.
  log_manager_.current_log()->set_hardware_class(hardware_class_);

  // Put incremental data (histogram deltas, and realtime stats deltas) at the
  // end of all log transmissions (initial log handles this separately).
  // RecordIncrementalStabilityElements only exists on the derived
  // MetricsLog class.
  MetricsLog* current_log =
      static_cast<MetricsLog*>(log_manager_.current_log());
  DCHECK(current_log);
  std::vector<chrome_variations::ActiveGroupId> synthetic_trials;
  GetCurrentSyntheticFieldTrials(&synthetic_trials);
  current_log->RecordEnvironment(plugins_, google_update_metrics_,
                                 synthetic_trials);
  PrefService* pref = g_browser_process->local_state();
  base::TimeDelta incremental_uptime;
  base::TimeDelta uptime;
  GetUptimes(pref, &incremental_uptime, &uptime);
  current_log->RecordStabilityMetrics(incremental_uptime, uptime,
                                      MetricsLog::ONGOING_LOG);

  RecordCurrentHistograms();

  log_manager_.FinishCurrentLog();
}

void MetricsService::PushPendingLogsToPersistentStorage() {
  if (state_ < SENDING_INITIAL_STABILITY_LOG)
    return;  // We didn't and still don't have time to get plugin list etc.

  if (log_manager_.has_staged_log()) {
    // We may race here, and send second copy of the log later.
    MetricsLogManager::StoreType store_type;
    if (current_fetch_.get())
      store_type = MetricsLogManager::PROVISIONAL_STORE;
    else
      store_type = MetricsLogManager::NORMAL_STORE;
    log_manager_.StoreStagedLogAsUnsent(store_type);
  }
  DCHECK(!log_manager_.has_staged_log());
  CloseCurrentLog();
  log_manager_.PersistUnsentLogs();

  // If there was a staged and/or current log, then there is now at least one
  // log waiting to be uploaded.
  if (log_manager_.has_unsent_logs())
    state_ = SENDING_OLD_LOGS;
}

//------------------------------------------------------------------------------
// Transmission of logs methods

void MetricsService::StartSchedulerIfNecessary() {
  // Never schedule cutting or uploading of logs in test mode.
  if (test_mode_active_)
    return;

  // Even if reporting is disabled, the scheduler is needed to trigger the
  // creation of the initial log, which must be done in order for any logs to be
  // persisted on shutdown or backgrounding.
  if (recording_active() &&
      (reporting_active() || state_ < SENDING_INITIAL_STABILITY_LOG)) {
    scheduler_->Start();
  }
}

void MetricsService::StartScheduledUpload() {
  // If we're getting no notifications, then the log won't have much in it, and
  // it's possible the computer is about to go to sleep, so don't upload and
  // stop the scheduler.
  // If recording has been turned off, the scheduler doesn't need to run.
  // If reporting is off, proceed if the initial log hasn't been created, since
  // that has to happen in order for logs to be cut and stored when persisting.
  // TODO(stuartmorgan): Call Stop() on the schedule when reporting and/or
  // recording are turned off instead of letting it fire and then aborting.
  if (idle_since_last_transmission_ ||
      !recording_active() ||
      (!reporting_active() && state_ >= SENDING_INITIAL_STABILITY_LOG)) {
    scheduler_->Stop();
    scheduler_->UploadCancelled();
    return;
  }

  // If the callback was to upload an old log, but there no longer is one,
  // just report success back to the scheduler to begin the ongoing log
  // callbacks.
  // TODO(stuartmorgan): Consider removing the distinction between
  // SENDING_OLD_LOGS and SENDING_CURRENT_LOGS to simplify the state machine
  // now that the log upload flow is the same for both modes.
  if (state_ == SENDING_OLD_LOGS && !log_manager_.has_unsent_logs()) {
    state_ = SENDING_CURRENT_LOGS;
    scheduler_->UploadFinished(true /* healthy */, false /* no unsent logs */);
    return;
  }
  // If there are unsent logs, send the next one. If not, start the asynchronous
  // process of finalizing the current log for upload.
  if (state_ == SENDING_OLD_LOGS) {
    DCHECK(log_manager_.has_unsent_logs());
    log_manager_.StageNextLogForUpload();
    SendStagedLog();
  } else {
    StartFinalLogInfoCollection();
  }
}

void MetricsService::StartFinalLogInfoCollection() {
  // Begin the multi-step process of collecting memory usage histograms:
  // First spawn a task to collect the memory details; when that task is
  // finished, it will call OnMemoryDetailCollectionDone. That will in turn
  // call HistogramSynchronization to collect histograms from all renderers and
  // then call OnHistogramSynchronizationDone to continue processing.
  DCHECK(!waiting_for_asynchronous_reporting_step_);
  waiting_for_asynchronous_reporting_step_ = true;

  base::Closure callback =
      base::Bind(&MetricsService::OnMemoryDetailCollectionDone,
                 self_ptr_factory_.GetWeakPtr());

  scoped_refptr<MetricsMemoryDetails> details(
      new MetricsMemoryDetails(callback));
  details->StartFetch(MemoryDetails::UPDATE_USER_METRICS);

  // Collect WebCore cache information to put into a histogram.
  for (content::RenderProcessHost::iterator i(
          content::RenderProcessHost::AllHostsIterator());
       !i.IsAtEnd(); i.Advance())
    i.GetCurrentValue()->Send(new ChromeViewMsg_GetCacheResourceStats());
}

void MetricsService::OnMemoryDetailCollectionDone() {
  DCHECK(IsSingleThreaded());
  // This function should only be called as the callback from an ansynchronous
  // step.
  DCHECK(waiting_for_asynchronous_reporting_step_);

  // Create a callback_task for OnHistogramSynchronizationDone.
  base::Closure callback = base::Bind(
      &MetricsService::OnHistogramSynchronizationDone,
      self_ptr_factory_.GetWeakPtr());

  base::TimeDelta timeout =
      base::TimeDelta::FromMilliseconds(kMaxHistogramGatheringWaitDuration);

  DCHECK_EQ(num_async_histogram_fetches_in_progress_, 0);

#if defined(OS_ANDROID)
  // Android has no service process.
  num_async_histogram_fetches_in_progress_ = 1;
#else  // OS_ANDROID
  num_async_histogram_fetches_in_progress_ = 2;
  // Run requests to service and content in parallel.
  if (!ServiceProcessControl::GetInstance()->GetHistograms(callback, timeout)) {
    // Assume |num_async_histogram_fetches_in_progress_| is not changed by
    // |GetHistograms()|.
    DCHECK_EQ(num_async_histogram_fetches_in_progress_, 2);
    // Assign |num_async_histogram_fetches_in_progress_| above and decrement it
    // here to make code work even if |GetHistograms()| fired |callback|.
    --num_async_histogram_fetches_in_progress_;
  }
#endif  // OS_ANDROID

  // Set up the callback to task to call after we receive histograms from all
  // child processes. Wait time specifies how long to wait before absolutely
  // calling us back on the task.
  content::FetchHistogramsAsynchronously(base::MessageLoop::current(), callback,
                                         timeout);
}

void MetricsService::OnHistogramSynchronizationDone() {
  DCHECK(IsSingleThreaded());
  // This function should only be called as the callback from an ansynchronous
  // step.
  DCHECK(waiting_for_asynchronous_reporting_step_);
  DCHECK_GT(num_async_histogram_fetches_in_progress_, 0);

  // Check if all expected requests finished.
  if (--num_async_histogram_fetches_in_progress_ > 0)
    return;

  waiting_for_asynchronous_reporting_step_ = false;
  OnFinalLogInfoCollectionDone();
}

void MetricsService::OnFinalLogInfoCollectionDone() {
  // If somehow there is a fetch in progress, we return and hope things work
  // out. The scheduler isn't informed since if this happens, the scheduler
  // will get a response from the upload.
  DCHECK(!current_fetch_.get());
  if (current_fetch_.get())
    return;

  // Abort if metrics were turned off during the final info gathering.
  if (!recording_active()) {
    scheduler_->Stop();
    scheduler_->UploadCancelled();
    return;
  }

  StageNewLog();

  // If logs shouldn't be uploaded, stop here. It's important that this check
  // be after StageNewLog(), otherwise the previous logs will never be loaded,
  // and thus the open log won't be persisted.
  // TODO(stuartmorgan): This is unnecessarily complicated; restructure loading
  // of previous logs to not require running part of the upload logic.
  // http://crbug.com/157337
  if (!reporting_active()) {
    scheduler_->Stop();
    scheduler_->UploadCancelled();
    return;
  }

  SendStagedLog();
}

void MetricsService::StageNewLog() {
  if (log_manager_.has_staged_log())
    return;

  switch (state_) {
    case INITIALIZED:
    case INIT_TASK_SCHEDULED:  // We should be further along by now.
      NOTREACHED();
      return;

    case INIT_TASK_DONE:
      if (has_initial_stability_log_) {
        // There's an initial stability log, ready to send.
        log_manager_.StageNextLogForUpload();
        has_initial_stability_log_ = false;
        // Note: No need to call LoadPersistedUnsentLogs() here because unsent
        // logs have already been loaded by PrepareInitialStabilityLog().
        state_ = SENDING_INITIAL_STABILITY_LOG;
      } else {
        // TODO(asvitkine): When the field trial is removed, the |log_type|
        // arg should be removed and PrepareInitialMetricsLog() should always
        // use ONGOING_LOG. Use INITIAL_LOG only to match to the old behavior
        // when the field trial is off.
        MetricsLog::LogType log_type = SendSeparateInitialStabilityLog() ?
            MetricsLog::ONGOING_LOG : MetricsLog::INITIAL_LOG;
        PrepareInitialMetricsLog(log_type);
        // Load unsent logs (if any) from local state.
        log_manager_.LoadPersistedUnsentLogs();
        state_ = SENDING_INITIAL_METRICS_LOG;
      }
      break;

    case SENDING_OLD_LOGS:
      NOTREACHED();  // Shouldn't be staging a new log during old log sending.
      return;

    case SENDING_CURRENT_LOGS:
      CloseCurrentLog();
      OpenNewLog();
      log_manager_.StageNextLogForUpload();
      break;

    default:
      NOTREACHED();
      return;
  }

  DCHECK(log_manager_.has_staged_log());
}

void MetricsService::PrepareInitialStabilityLog() {
  DCHECK_EQ(INITIALIZED, state_);
  PrefService* pref = g_browser_process->local_state();
  DCHECK_NE(0, pref->GetInteger(prefs::kStabilityCrashCount));

  scoped_ptr<MetricsLog> initial_stability_log(
      new MetricsLog(client_id_, session_id_));
  if (!initial_stability_log->LoadSavedEnvironmentFromPrefs())
    return;
  initial_stability_log->RecordStabilityMetrics(
      base::TimeDelta(), base::TimeDelta(), MetricsLog::INITIAL_LOG);
  log_manager_.LoadPersistedUnsentLogs();

  log_manager_.PauseCurrentLog();
  log_manager_.BeginLoggingWithLog(initial_stability_log.release(),
                                   MetricsLog::INITIAL_LOG);
#if defined(OS_ANDROID)
  ConvertAndroidStabilityPrefsToHistograms(pref);
  RecordCurrentStabilityHistograms();
#endif  // defined(OS_ANDROID)
  log_manager_.FinishCurrentLog();
  log_manager_.ResumePausedLog();

  // Store unsent logs, including the stability log that was just saved, so
  // that they're not lost in case of a crash before upload time.
  log_manager_.PersistUnsentLogs();

  has_initial_stability_log_ = true;
}

void MetricsService::PrepareInitialMetricsLog(MetricsLog::LogType log_type) {
  DCHECK(state_ == INIT_TASK_DONE || state_ == SENDING_INITIAL_STABILITY_LOG);
  initial_metrics_log_->set_hardware_class(hardware_class_);

  std::vector<chrome_variations::ActiveGroupId> synthetic_trials;
  GetCurrentSyntheticFieldTrials(&synthetic_trials);
  initial_metrics_log_->RecordEnvironment(plugins_, google_update_metrics_,
                                          synthetic_trials);
  PrefService* pref = g_browser_process->local_state();
  base::TimeDelta incremental_uptime;
  base::TimeDelta uptime;
  GetUptimes(pref, &incremental_uptime, &uptime);
  initial_metrics_log_->RecordStabilityMetrics(incremental_uptime, uptime,
                                               log_type);

  // Histograms only get written to the current log, so make the new log current
  // before writing them.
  log_manager_.PauseCurrentLog();
  log_manager_.BeginLoggingWithLog(initial_metrics_log_.release(), log_type);
#if defined(OS_ANDROID)
  ConvertAndroidStabilityPrefsToHistograms(pref);
#endif  // defined(OS_ANDROID)
  RecordCurrentHistograms();
  log_manager_.FinishCurrentLog();
  log_manager_.ResumePausedLog();

  DCHECK(!log_manager_.has_staged_log());
  log_manager_.StageNextLogForUpload();
}

void MetricsService::SendStagedLog() {
  DCHECK(log_manager_.has_staged_log());

  PrepareFetchWithStagedLog();

  bool upload_created = (current_fetch_.get() != NULL);
  UMA_HISTOGRAM_BOOLEAN("UMA.UploadCreation", upload_created);
  if (!upload_created) {
    // Compression failed, and log discarded :-/.
    // Skip this upload and hope things work out next time.
    log_manager_.DiscardStagedLog();
    scheduler_->UploadCancelled();
    return;
  }

  DCHECK(!waiting_for_asynchronous_reporting_step_);
  waiting_for_asynchronous_reporting_step_ = true;

  current_fetch_->Start();

  HandleIdleSinceLastTransmission(true);
}

void MetricsService::PrepareFetchWithStagedLog() {
  DCHECK(log_manager_.has_staged_log());

  // Prepare the protobuf version.
  DCHECK(!current_fetch_.get());
  if (log_manager_.has_staged_log()) {
    current_fetch_.reset(net::URLFetcher::Create(
        GURL(kServerUrl), net::URLFetcher::POST, this));
    current_fetch_->SetRequestContext(
        g_browser_process->system_request_context());

    std::string log_text = log_manager_.staged_log_text();
    std::string compressed_log_text;
    bool compression_successful = chrome::GzipCompress(log_text,
                                                       &compressed_log_text);
    DCHECK(compression_successful);
    if (compression_successful) {
      current_fetch_->SetUploadData(kMimeType, compressed_log_text);
      // Tell the server that we're uploading gzipped protobufs.
      current_fetch_->SetExtraRequestHeaders("content-encoding: gzip");
      const std::string hash =
          base::HexEncode(log_manager_.staged_log_hash().data(),
                          log_manager_.staged_log_hash().size());
      DCHECK(!hash.empty());
      current_fetch_->AddExtraRequestHeader("X-Chrome-UMA-Log-SHA1: " + hash);
      UMA_HISTOGRAM_PERCENTAGE(
          "UMA.ProtoCompressionRatio",
          100 * compressed_log_text.size() / log_text.size());
      UMA_HISTOGRAM_CUSTOM_COUNTS(
          "UMA.ProtoGzippedKBSaved",
          (log_text.size() - compressed_log_text.size()) / 1024,
          1, 2000, 50);
    }

    // We already drop cookies server-side, but we might as well strip them out
    // client-side as well.
    current_fetch_->SetLoadFlags(net::LOAD_DO_NOT_SAVE_COOKIES |
                                 net::LOAD_DO_NOT_SEND_COOKIES);
  }
}

void MetricsService::OnURLFetchComplete(const net::URLFetcher* source) {
  DCHECK(waiting_for_asynchronous_reporting_step_);

  // We're not allowed to re-use the existing |URLFetcher|s, so free them here.
  // Note however that |source| is aliased to the fetcher, so we should be
  // careful not to delete it too early.
  DCHECK_EQ(current_fetch_.get(), source);
  scoped_ptr<net::URLFetcher> s(current_fetch_.Pass());

  int response_code = source->GetResponseCode();

  // Log a histogram to track response success vs. failure rates.
  UMA_HISTOGRAM_ENUMERATION("UMA.UploadResponseStatus.Protobuf",
                            ResponseCodeToStatus(response_code),
                            NUM_RESPONSE_STATUSES);

  // If the upload was provisionally stored, drop it now that the upload is
  // known to have gone through.
  log_manager_.DiscardLastProvisionalStore();

  bool upload_succeeded = response_code == 200;

  // Provide boolean for error recovery (allow us to ignore response_code).
  bool discard_log = false;
  const size_t log_size = log_manager_.staged_log_text().length();
  if (!upload_succeeded && log_size > kUploadLogAvoidRetransmitSize) {
    UMA_HISTOGRAM_COUNTS("UMA.Large Rejected Log was Discarded",
                         static_cast<int>(log_size));
    discard_log = true;
  } else if (response_code == 400) {
    // Bad syntax.  Retransmission won't work.
    discard_log = true;
  }

  if (upload_succeeded || discard_log)
    log_manager_.DiscardStagedLog();

  waiting_for_asynchronous_reporting_step_ = false;

  if (!log_manager_.has_staged_log()) {
    switch (state_) {
      case SENDING_INITIAL_STABILITY_LOG:
        // Store the updated list to disk now that the removed log is uploaded.
        log_manager_.PersistUnsentLogs();
        PrepareInitialMetricsLog(MetricsLog::ONGOING_LOG);
        SendStagedLog();
        state_ = SENDING_INITIAL_METRICS_LOG;
        break;

      case SENDING_INITIAL_METRICS_LOG:
        // The initial metrics log never gets persisted to local state, so it's
        // not necessary to call log_manager_.PersistUnsentLogs() here.
        // TODO(asvitkine): It should be persisted like the initial stability
        // log and old unsent logs. http://crbug.com/328417
        state_ = log_manager_.has_unsent_logs() ? SENDING_OLD_LOGS
                                                : SENDING_CURRENT_LOGS;
        break;

      case SENDING_OLD_LOGS:
        // Store the updated list to disk now that the removed log is uploaded.
        log_manager_.PersistUnsentLogs();
        if (!log_manager_.has_unsent_logs())
          state_ = SENDING_CURRENT_LOGS;
        break;

      case SENDING_CURRENT_LOGS:
        break;

      default:
        NOTREACHED();
        break;
    }

    if (log_manager_.has_unsent_logs())
      DCHECK_LT(state_, SENDING_CURRENT_LOGS);
  }

  // Error 400 indicates a problem with the log, not with the server, so
  // don't consider that a sign that the server is in trouble.
  bool server_is_healthy = upload_succeeded || response_code == 400;
  // Don't notify the scheduler that the upload is finished if we've only sent
  // the initial stability log, but not yet the initial metrics log (treat the
  // two as a single unit of work as far as the scheduler is concerned).
  if (state_ != SENDING_INITIAL_METRICS_LOG) {
    scheduler_->UploadFinished(server_is_healthy,
                               log_manager_.has_unsent_logs());
  }

  // Collect network stats if UMA upload succeeded.
  IOThread* io_thread = g_browser_process->io_thread();
  if (server_is_healthy && io_thread) {
    chrome_browser_net::CollectNetworkStats(network_stats_server_, io_thread);
    chrome_browser_net::CollectPipeliningCapabilityStatsOnUIThread(
        http_pipelining_test_server_, io_thread);
#if defined(OS_WIN)
    chrome::CollectTimeTicksStats();
#endif
  }
}

void MetricsService::IncrementPrefValue(const char* path) {
  PrefService* pref = g_browser_process->local_state();
  DCHECK(pref);
  int value = pref->GetInteger(path);
  pref->SetInteger(path, value + 1);
}

void MetricsService::IncrementLongPrefsValue(const char* path) {
  PrefService* pref = g_browser_process->local_state();
  DCHECK(pref);
  int64 value = pref->GetInt64(path);
  pref->SetInt64(path, value + 1);
}

void MetricsService::LogLoadStarted(content::WebContents* web_contents) {
  content::RecordAction(base::UserMetricsAction("PageLoad"));
  HISTOGRAM_ENUMERATION("Chrome.UmaPageloadCounter", 1, 2);
  IncrementPrefValue(prefs::kStabilityPageLoadCount);
  IncrementLongPrefsValue(prefs::kUninstallMetricsPageLoadCount);
  // We need to save the prefs, as page load count is a critical stat, and it
  // might be lost due to a crash :-(.
}

void MetricsService::LogRendererCrash(content::RenderProcessHost* host,
                                      base::TerminationStatus status,
                                      int exit_code) {
  bool was_extension_process =
      extensions::ProcessMap::Get(host->GetBrowserContext())
          ->Contains(host->GetID());
  if (status == base::TERMINATION_STATUS_PROCESS_CRASHED ||
      status == base::TERMINATION_STATUS_ABNORMAL_TERMINATION) {
    if (was_extension_process) {
      IncrementPrefValue(prefs::kStabilityExtensionRendererCrashCount);

      UMA_HISTOGRAM_SPARSE_SLOWLY("CrashExitCodes.Extension",
                                  MapCrashExitCodeForHistogram(exit_code));
    } else {
      IncrementPrefValue(prefs::kStabilityRendererCrashCount);

      UMA_HISTOGRAM_SPARSE_SLOWLY("CrashExitCodes.Renderer",
                                  MapCrashExitCodeForHistogram(exit_code));
    }

    UMA_HISTOGRAM_PERCENTAGE("BrowserRenderProcessHost.ChildCrashes",
                             was_extension_process ? 2 : 1);
  } else if (status == base::TERMINATION_STATUS_PROCESS_WAS_KILLED) {
    UMA_HISTOGRAM_PERCENTAGE("BrowserRenderProcessHost.ChildKills",
                             was_extension_process ? 2 : 1);
  } else if (status == base::TERMINATION_STATUS_STILL_RUNNING) {
    UMA_HISTOGRAM_PERCENTAGE("BrowserRenderProcessHost.DisconnectedAlive",
                               was_extension_process ? 2 : 1);
  }
}

void MetricsService::LogRendererHang() {
  IncrementPrefValue(prefs::kStabilityRendererHangCount);
}

bool MetricsService::UmaMetricsProperlyShutdown() {
  CHECK(clean_shutdown_status_ == CLEANLY_SHUTDOWN ||
        clean_shutdown_status_ == NEED_TO_SHUTDOWN);
  return clean_shutdown_status_ == CLEANLY_SHUTDOWN;
}

void MetricsService::RegisterSyntheticFieldTrial(
    const SyntheticTrialGroup& trial) {
  for (size_t i = 0; i < synthetic_trial_groups_.size(); ++i) {
    if (synthetic_trial_groups_[i].id.name == trial.id.name) {
      if (synthetic_trial_groups_[i].id.group != trial.id.group) {
        synthetic_trial_groups_[i].id.group = trial.id.group;
        synthetic_trial_groups_[i].start_time = base::TimeTicks::Now();
      }
      return;
    }
  }

  SyntheticTrialGroup trial_group = trial;
  trial_group.start_time = base::TimeTicks::Now();
  synthetic_trial_groups_.push_back(trial_group);
}

void MetricsService::CheckForClonedInstall() {
  DCHECK(!cloned_install_detector_);

  metrics::MachineIdProvider* provider =
      metrics::MachineIdProvider::CreateInstance();
  if (!provider)
    return;

  cloned_install_detector_.reset(
      new metrics::ClonedInstallDetector(provider));

  PrefService* local_state = g_browser_process->local_state();
  cloned_install_detector_->CheckForClonedInstall(local_state);
}

void MetricsService::GetCurrentSyntheticFieldTrials(
    std::vector<chrome_variations::ActiveGroupId>* synthetic_trials) {
  DCHECK(synthetic_trials);
  synthetic_trials->clear();
  const MetricsLog* current_log =
      static_cast<const MetricsLog*>(log_manager_.current_log());
  for (size_t i = 0; i < synthetic_trial_groups_.size(); ++i) {
    if (synthetic_trial_groups_[i].start_time <= current_log->creation_time())
      synthetic_trials->push_back(synthetic_trial_groups_[i].id);
  }
}

void MetricsService::LogCleanShutdown() {
  // Redundant hack to write pref ASAP.
  MarkAppCleanShutdownAndCommit();

  // Redundant setting to assure that we always reset this value at shutdown
  // (and that we don't use some alternate path, and not call LogCleanShutdown).
  clean_shutdown_status_ = CLEANLY_SHUTDOWN;

  RecordBooleanPrefValue(prefs::kStabilityExitedCleanly, true);
  PrefService* pref = g_browser_process->local_state();
  pref->SetInteger(prefs::kStabilityExecutionPhase,
                   MetricsService::SHUTDOWN_COMPLETE);
}

#if defined(OS_CHROMEOS)
void MetricsService::LogChromeOSCrash(const std::string &crash_type) {
  if (crash_type == "user")
    IncrementPrefValue(prefs::kStabilityOtherUserCrashCount);
  else if (crash_type == "kernel")
    IncrementPrefValue(prefs::kStabilityKernelCrashCount);
  else if (crash_type == "uncleanshutdown")
    IncrementPrefValue(prefs::kStabilitySystemUncleanShutdownCount);
  else
    NOTREACHED() << "Unexpected Chrome OS crash type " << crash_type;
  // Wake up metrics logs sending if necessary now that new
  // log data is available.
  HandleIdleSinceLastTransmission(false);
}
#endif  // OS_CHROMEOS

void MetricsService::LogPluginLoadingError(const base::FilePath& plugin_path) {
  content::WebPluginInfo plugin;
  bool success =
      content::PluginService::GetInstance()->GetPluginInfoByPath(plugin_path,
                                                                 &plugin);
  DCHECK(success);
  ChildProcessStats& stats = child_process_stats_buffer_[plugin.name];
  // Initialize the type if this entry is new.
  if (stats.process_type == content::PROCESS_TYPE_UNKNOWN) {
    // The plug-in process might not actually of type PLUGIN (which means
    // NPAPI), but we only care that it is *a* plug-in process.
    stats.process_type = content::PROCESS_TYPE_PLUGIN;
  } else {
    DCHECK(IsPluginProcess(stats.process_type));
  }
  stats.loading_errors++;
}

MetricsService::ChildProcessStats& MetricsService::GetChildProcessStats(
    const content::ChildProcessData& data) {
  const base::string16& child_name = data.name;
  if (!ContainsKey(child_process_stats_buffer_, child_name)) {
    child_process_stats_buffer_[child_name] =
        ChildProcessStats(data.process_type);
  }
  return child_process_stats_buffer_[child_name];
}

void MetricsService::RecordPluginChanges(PrefService* pref) {
  ListPrefUpdate update(pref, prefs::kStabilityPluginStats);
  base::ListValue* plugins = update.Get();
  DCHECK(plugins);

  for (base::ListValue::iterator value_iter = plugins->begin();
       value_iter != plugins->end(); ++value_iter) {
    if (!(*value_iter)->IsType(base::Value::TYPE_DICTIONARY)) {
      NOTREACHED();
      continue;
    }

    base::DictionaryValue* plugin_dict =
        static_cast<base::DictionaryValue*>(*value_iter);
    std::string plugin_name;
    plugin_dict->GetString(prefs::kStabilityPluginName, &plugin_name);
    if (plugin_name.empty()) {
      NOTREACHED();
      continue;
    }

    // TODO(viettrungluu): remove conversions
    base::string16 name16 = base::UTF8ToUTF16(plugin_name);
    if (child_process_stats_buffer_.find(name16) ==
        child_process_stats_buffer_.end()) {
      continue;
    }

    ChildProcessStats stats = child_process_stats_buffer_[name16];
    if (stats.process_launches) {
      int launches = 0;
      plugin_dict->GetInteger(prefs::kStabilityPluginLaunches, &launches);
      launches += stats.process_launches;
      plugin_dict->SetInteger(prefs::kStabilityPluginLaunches, launches);
    }
    if (stats.process_crashes) {
      int crashes = 0;
      plugin_dict->GetInteger(prefs::kStabilityPluginCrashes, &crashes);
      crashes += stats.process_crashes;
      plugin_dict->SetInteger(prefs::kStabilityPluginCrashes, crashes);
    }
    if (stats.instances) {
      int instances = 0;
      plugin_dict->GetInteger(prefs::kStabilityPluginInstances, &instances);
      instances += stats.instances;
      plugin_dict->SetInteger(prefs::kStabilityPluginInstances, instances);
    }
    if (stats.loading_errors) {
      int loading_errors = 0;
      plugin_dict->GetInteger(prefs::kStabilityPluginLoadingErrors,
                              &loading_errors);
      loading_errors += stats.loading_errors;
      plugin_dict->SetInteger(prefs::kStabilityPluginLoadingErrors,
                              loading_errors);
    }

    child_process_stats_buffer_.erase(name16);
  }

  // Now go through and add dictionaries for plugins that didn't already have
  // reports in Local State.
  for (std::map<base::string16, ChildProcessStats>::iterator cache_iter =
           child_process_stats_buffer_.begin();
       cache_iter != child_process_stats_buffer_.end(); ++cache_iter) {
    ChildProcessStats stats = cache_iter->second;

    // Insert only plugins information into the plugins list.
    if (!IsPluginProcess(stats.process_type))
      continue;

    // TODO(viettrungluu): remove conversion
    std::string plugin_name = base::UTF16ToUTF8(cache_iter->first);

    base::DictionaryValue* plugin_dict = new base::DictionaryValue;

    plugin_dict->SetString(prefs::kStabilityPluginName, plugin_name);
    plugin_dict->SetInteger(prefs::kStabilityPluginLaunches,
                            stats.process_launches);
    plugin_dict->SetInteger(prefs::kStabilityPluginCrashes,
                            stats.process_crashes);
    plugin_dict->SetInteger(prefs::kStabilityPluginInstances,
                            stats.instances);
    plugin_dict->SetInteger(prefs::kStabilityPluginLoadingErrors,
                            stats.loading_errors);
    plugins->Append(plugin_dict);
  }
  child_process_stats_buffer_.clear();
}

bool MetricsService::ShouldLogEvents() {
  // We simply don't log events to UMA if there is a single incognito
  // session visible. The problem is that we always notify using the orginal
  // profile in order to simplify notification processing.
  return !chrome::IsOffTheRecordSessionActive();
}

void MetricsService::RecordBooleanPrefValue(const char* path, bool value) {
  DCHECK(IsSingleThreaded());

  PrefService* pref = g_browser_process->local_state();
  DCHECK(pref);

  pref->SetBoolean(path, value);
  RecordCurrentState(pref);
}

void MetricsService::RecordCurrentState(PrefService* pref) {
  pref->SetInt64(prefs::kStabilityLastTimestampSec, Time::Now().ToTimeT());

  RecordPluginChanges(pref);
}

// static
bool MetricsService::IsPluginProcess(int process_type) {
  return (process_type == content::PROCESS_TYPE_PLUGIN ||
          process_type == content::PROCESS_TYPE_PPAPI_PLUGIN ||
          process_type == content::PROCESS_TYPE_PPAPI_BROKER);
}

#if defined(OS_CHROMEOS)
void MetricsService::StartExternalMetrics() {
  external_metrics_ = new chromeos::ExternalMetrics;
  external_metrics_->Start();
}
#endif

// static
bool MetricsServiceHelper::IsMetricsReportingEnabled() {
  bool result = false;
  const PrefService* local_state = g_browser_process->local_state();
  if (local_state) {
    const PrefService::Preference* uma_pref =
        local_state->FindPreference(prefs::kMetricsReportingEnabled);
    if (uma_pref) {
      bool success = uma_pref->GetValue()->GetAsBoolean(&result);
      DCHECK(success);
    }
  }
  return result;
}

bool MetricsServiceHelper::IsCrashReportingEnabled() {
#if defined(GOOGLE_CHROME_BUILD)
#if defined(OS_CHROMEOS)
  bool reporting_enabled = false;
  chromeos::CrosSettings::Get()->GetBoolean(chromeos::kStatsReportingPref,
                                            &reporting_enabled);
  return reporting_enabled;
#elif defined(OS_ANDROID)
  // Android has its own settings for metrics / crash uploading.
  const PrefService* prefs = g_browser_process->local_state();
  return prefs->GetBoolean(prefs::kCrashReportingEnabled);
#else
  return MetricsServiceHelper::IsMetricsReportingEnabled();
#endif
#else
  return false;
#endif
}