Refactor MetricsStateManager class out of MetricsService.

chrome/browser/metrics/metrics_service.h

 // 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.
 
 // This file defines a service that collects information about the user
 // experience in order to help improve future versions of the app.
 
 #ifndef CHROME_BROWSER_METRICS_METRICS_SERVICE_H_
 #define CHROME_BROWSER_METRICS_METRICS_SERVICE_H_
 
@@ skipping 52 matching lines @@
 }
 
 namespace extensions {
 class ExtensionDownloader;
 class ManifestFetchData;
 class MetricsPrivateGetIsCrashReportingEnabledFunction;
 }
 
 namespace metrics {
 class ClonedInstallDetector;
+class MetricsStateManager;
 }
 
 namespace net {
 class URLFetcher;
 }
 
 namespace prerender {
 bool IsOmniboxEnabled(Profile* profile);
 }
 
@@ skipping 50 matching lines @@
   };
 
   MetricsService();
   virtual ~MetricsService();
 
   // Initializes metrics recording state. Updates various bookkeeping values in
   // prefs and sets up the scheduler. This is a separate function rather than
   // being done by the constructor so that field trials could be created before
   // this is run. Takes |reporting_state| parameter which specifies whether UMA
   // is enabled.
-  void InitializeMetricsRecordingState(ReportingState reporting_state);
+  void InitializeMetricsRecordingState();
 
   // Starts the metrics system, turning on recording and uploading of metrics.
   // Should be called when starting up with metrics enabled, or when metrics
   // are turned on.
   void Start();
 
+  // If metrics reporting is enabled, starts the metrics service. Returns
+  // whether the metrics service was started.
+  bool StartIfMetricsReportingEnabled();
+
   // Starts the metrics system in a special test-only mode. Metrics won't ever
   // be uploaded or persisted in this mode, but metrics will be recorded in
   // memory.
   void StartRecordingForTests();
 
   // Shuts down the metrics system. Should be called at shutdown, or if metrics
   // are turned off.
   void Stop();
 
   // Enable/disable transmission of accumulated logs and crash reports (dumps).
   // Calling Start() automatically enables reporting, but sending is
   // asyncronous so this can be called immediately after Start() to prevent
   // any uploading.
   void EnableReporting();
   void DisableReporting();
 
   // Returns the client ID for this client, or the empty string if metrics
   // recording is not currently running.
   std::string GetClientId();
 
   // Returns the preferred entropy provider used to seed persistent activities

[jwd, 2014/05/01 15:51:14]

Update comment.

[Alexei Svitkine (slow), 2014/05/01 18:01:45]

Done.

   // based on whether or not metrics reporting will be permitted on this client.
   // The caller must determine if metrics reporting will be enabled for this
   // client and pass that state in as |reporting_will_be_enabled|.
   //
   // If |reporting_will_be_enabled| is true, this method returns an entropy
   // provider that has a high source of entropy, partially based on the client
   // ID. Otherwise, an entropy provider that is based on a low entropy source
   // is returned.
   //
   // Note that this reporting state can not be checked by reporting_active()
   // because this method may need to be called before the MetricsService needs
   // to be started.
-  scoped_ptr<const base::FieldTrial::EntropyProvider> CreateEntropyProvider(
-      ReportingState reporting_state);
+  scoped_ptr<const base::FieldTrial::EntropyProvider> CreateEntropyProvider();
 
   // Force the client ID to be generated. This is useful in case it's needed
   // before recording.
   void ForceClientIdCreation();

[jwd, 2014/05/01 15:51:14]

Is this still needed in the metrics service? 

[Alexei Svitkine (slow), 2014/05/01 18:01:45]

No, it's not. Good catch!

 
   // At startup, prefs needs to be called with a list of all the pref names and
   // types we'll be using.
   static void RegisterPrefs(PrefRegistrySimple* registry);
 #if defined(OS_ANDROID)
   static void RegisterPrefsAndroid(PrefRegistrySimple* registry);
 #endif  // defined(OS_ANDROID)
 
   // Set up notifications which indicate that a user is performing work. This is
   // useful to allow some features to sleep, until the machine becomes active,
@@ skipping 162 matching lines @@
   // Get the amount of uptime since this process started and since the last
   // call to this function.  Also updates the cumulative uptime metric (stored
   // as a pref) for uninstall.  Uptimes are measured using TimeTicks, which
   // guarantees that it is monotonic and does not jump if the user changes
   // his/her clock.  The TimeTicks implementation also makes the clock not
   // count time the computer is suspended.
   void GetUptimes(PrefService* pref,
                   base::TimeDelta* incremental_uptime,
                   base::TimeDelta* uptime);
 
-  // Reset the client id and low entropy source if the kMetricsResetMetricIDs
-  // pref is true.
-  void ResetMetricsIDsIfNecessary();
-
-  // Returns the low entropy source for this client. This is a random value
-  // that is non-identifying amongst browser clients. This method will
-  // generate the entropy source value if it has not been called before.
-  int GetLowEntropySource();
-
-  // Returns the first entropy source that was returned by this service since
-  // start up, or NONE if neither was returned yet. This is exposed for testing
-  // only.
-  EntropySourceReturned entropy_source_returned() const {
-    return entropy_source_returned_;
-  }
-
   // Turns recording on or off.
   // DisableRecording() also forces a persistent save of logging state (if
   // anything has been recorded, or transmitted).
   void EnableRecording();
   void DisableRecording();
 
   // If in_idle is true, sets idle_since_last_transmission to true.
   // If in_idle is false and idle_since_last_transmission_ is true, sets
   // idle_since_last_transmission to false and starts the timer (provided
   // starting the timer is permitted).
   void HandleIdleSinceLastTransmission(bool in_idle);
 
   // Set up client ID, session ID, etc.
-  void InitializeMetricsState(ReportingState reporting_state);
-
-  // Generates a new client ID to use to identify self to metrics server.
-  static std::string GenerateClientID();
+  void InitializeMetricsState();
 
   // Schedule the next save of LocalState information.  This is called
   // automatically by the task that performs each save to schedule the next one.
   void ScheduleNextStateSave();
 
   // Save the LocalState information immediately. This should not be called by
   // anybody other than the scheduler to avoid doing too many writes. When you
   // make a change, call ScheduleNextStateSave() instead.
   void SaveLocalState();
 
@@ skipping 91 matching lines @@
 
   // Returns true if process of type |type| should be counted as a plugin
   // process, and false otherwise.
   static bool IsPluginProcess(int process_type);
 
   // Returns a list of synthetic field trials that were active for the entire
   // duration of the current log.
   void GetCurrentSyntheticFieldTrials(
       std::vector<chrome_variations::ActiveGroupId>* synthetic_trials);
 
+  scoped_ptr<metrics::MetricsStateManager> state_manager_;
+
   base::ActionCallback action_callback_;
 
   content::NotificationRegistrar registrar_;
 
   // Set to true when |ResetMetricsIDsIfNecessary| is called for the first time.
   // This prevents multiple resets within the same Chrome session.
   bool metrics_ids_reset_check_performed_;
 
   // Indicate whether recording and reporting are currently happening.
   // These should not be set directly, but by calling SetRecording and
@@ skipping 31 matching lines @@
 
   // The outstanding transmission appears as a URL Fetch operation.
   scoped_ptr<net::URLFetcher> current_fetch_;
 
   // The TCP/UDP echo server to collect network connectivity stats.
   std::string network_stats_server_;
 
   // The HTTP pipelining test server.
   std::string http_pipelining_test_server_;
 
-  // The identifier that's sent to the server with the log reports.
-  std::string client_id_;
-
-  // The non-identifying low entropy source value.
-  int low_entropy_source_;
-
   // Whether the MetricsService object has received any notifications since
   // the last time a transmission was sent.
   bool idle_since_last_transmission_;
 
   // A number that identifies the how many times the app has been launched.
   int session_id_;
 
   // Maps WebContentses (corresponding to tabs) or Browsers (corresponding to
   // Windows) to a unique integer that we will use to identify them.
   // |next_window_id_| is used to track which IDs we have used so far.
@@ skipping 20 matching lines @@
   bool waiting_for_asynchronous_reporting_step_;
 
   // Number of async histogram fetch requests in progress.
   int num_async_histogram_fetches_in_progress_;
 
 #if defined(OS_CHROMEOS)
   // The external metric service is used to log ChromeOS UMA events.
   scoped_refptr<chromeos::ExternalMetrics> external_metrics_;
 #endif
 
-  // The last entropy source returned by this service, used for testing.
-  EntropySourceReturned entropy_source_returned_;
-
   // Stores the time of the first call to |GetUptimes()|.
   base::TimeTicks first_updated_time_;
 
   // Stores the time of the last call to |GetUptimes()|.
   base::TimeTicks last_updated_time_;
 
   // Execution phase the browser is in.
   static ExecutionPhase execution_phase_;
 
   // Reduntant marker to check that we completed our shutdown, and set the
   // exited-cleanly bit in the prefs.
   static ShutdownCleanliness clean_shutdown_status_;
 
   // Field trial groups that map to Chrome configuration states.
   SyntheticTrialGroups synthetic_trial_groups_;
 
-  scoped_ptr<metrics::ClonedInstallDetector> cloned_install_detector_;
-
-  FRIEND_TEST_ALL_PREFIXES(MetricsServiceTest, ClientIdCorrectlyFormatted);
   FRIEND_TEST_ALL_PREFIXES(MetricsServiceTest, IsPluginProcess);
-  FRIEND_TEST_ALL_PREFIXES(MetricsServiceTest, LowEntropySource0NotReset);
   FRIEND_TEST_ALL_PREFIXES(MetricsServiceTest,
                            PermutedEntropyCacheClearedWhenLowEntropyReset);
   FRIEND_TEST_ALL_PREFIXES(MetricsServiceTest, RegisterSyntheticTrial);
-  FRIEND_TEST_ALL_PREFIXES(MetricsServiceTest, ResetMetricsIDs);
-  FRIEND_TEST_ALL_PREFIXES(MetricsServiceBrowserTest,
-                           CheckLowEntropySourceUsed);
-  FRIEND_TEST_ALL_PREFIXES(MetricsServiceReportingTest,
-                           CheckHighEntropySourceUsed);
 
   DISALLOW_COPY_AND_ASSIGN(MetricsService);
 };
 
 // This class limits and documents access to the IsMetricsReportingEnabled() and
 // IsCrashReportingEnabled() methods. Since these methods are private, each user
 // has to be explicitly declared as a 'friend' below.
 class MetricsServiceHelper {
  private:
   friend bool prerender::IsOmniboxEnabled(Profile* profile);
@@ skipping 12 matching lines @@
 
   // Returns true if crash reporting is enabled.  This is set at the platform
   // level for Android and ChromeOS, and otherwise is the same as
   // IsMetricsReportingEnabled for desktop Chrome.
   static bool IsCrashReportingEnabled();
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(MetricsServiceHelper);
 };
 
 #endif  // CHROME_BROWSER_METRICS_METRICS_SERVICE_H_