Record the number of tabs in a session restore in SampledProfile

chrome/browser/metrics/perf_provider_chromeos.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.
 
 #ifndef CHROME_BROWSER_METRICS_PERF_PROVIDER_CHROMEOS_H_
 #define CHROME_BROWSER_METRICS_PERF_PROVIDER_CHROMEOS_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 43 matching lines @@
   // Called when a suspend finishes. This is either a successful suspend
   // followed by a resume, or a suspend that was canceled. Inherited from
   // PowerManagerClient::Observer.
   void SuspendDone(const base::TimeDelta& sleep_duration) override;
 
   // Turns on perf collection. Resets the timer that's used to schedule
   // collections.
   void OnUserLoggedIn();
 
   // Called when a session restore has finished.
-  void OnSessionRestoreDone();
+  void OnSessionRestoreDone(int num_tabs_restored);

[Ilya Sherman, 2015/02/04 22:50:53]

nit: size_t?

[Simon Que, 2015/02/05 00:16:01]

It's an int32 in the protobuf, so we should just use an int:
https://code.google.com/p/chromium/codesearch#chromium/src/components/metrics...

 
   // Turns off perf collection. Does not delete any data that was already
   // collected and stored in |cached_perf_data_|.
   void Deactivate();
 
   // Selects a random time in the upcoming profiling interval that begins at
   // |next_profiling_interval_start_|. Schedules |timer_| to invoke
   // DoPeriodicCollection() when that time comes.
   void ScheduleIntervalCollection();
 
   // Collects perf data for a given |trigger_event|. Calls perf via the ChromeOS
   // debug daemon's dbus interface.
   void CollectIfNecessary(scoped_ptr<SampledProfile> sampled_profile);
 
   // Collects perf data on a repeating basis by calling CollectIfNecessary() and
   // reschedules it to be collected again.
   void DoPeriodicCollection();
 
   // Collects perf data after a resume. |sleep_duration| is the duration the
   // system was suspended before resuming. |time_after_resume_ms| is how long
   // ago the system resumed.
   void CollectPerfDataAfterResume(const base::TimeDelta& sleep_duration,
                                   const base::TimeDelta& time_after_resume);
 
   // Collects perf data after a session restore. |time_after_restore| is how
-  // long ago the session restore started.
+  // long ago the session restore started. |num_tabs_restored| is the total
+  // number of tabs being restored.
   void CollectPerfDataAfterSessionRestore(
-      const base::TimeDelta& time_after_restore);
+      const base::TimeDelta& time_after_restore,
+      int num_tabs_restored);
 
   // Parses a perf data protobuf from the |data| passed in only if the
   // |incognito_observer| indicates that no incognito window had been opened
   // during the profile collection period.
   // |trigger_event| is the cause of the perf data collection.
   void ParseProtoIfValid(
       scoped_ptr<WindowedIncognitoObserver> incognito_observer,
       scoped_ptr<SampledProfile> sampled_profile,
       const std::vector<uint8>& data);
 
@@ skipping 25 matching lines @@
 
   // To pass around the "this" pointer across threads safely.
   base::WeakPtrFactory<PerfProvider> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(PerfProvider);
 };
 
 }  // namespace metrics
 
 #endif  // CHROME_BROWSER_METRICS_PERF_PROVIDER_CHROMEOS_H_