Delivering the FIRST_NONEMPTY_PAINT phase changing event to base/

components/metrics/profiler/tracking_synchronizer.h

Index: components/metrics/profiler/tracking_synchronizer.h
diff --git a/components/metrics/profiler/tracking_synchronizer.h b/components/metrics/profiler/tracking_synchronizer.h
index 472b45ca311c4b14766104f10cd8024554cfd9fe..01542dc4450b00eb09dd78beabfb0dd1a78e91a3 100644
--- a/components/metrics/profiler/tracking_synchronizer.h
+++ b/components/metrics/profiler/tracking_synchronizer.h
@@ -54,6 +54,11 @@ class TrackingSynchronizer
   static void FetchProfilerDataAsynchronously(
       const base::WeakPtr<TrackingSynchronizerObserver>& callback_object);
 
+  // Called when a profiling phase completes. |profiling_event| is the event
+  // associated with completing the phase and starting a new one.
+  static void OnProfilingPhaseCompletion(
+      ProfilerEventProto::ProfilerEvent profiling_event);
+
   // ------------------------------------------------------
   // ProfilerSubscriber methods for browser child processes
   // ------------------------------------------------------
@@ -64,15 +69,28 @@ class TrackingSynchronizer
                           int pending_processes,
                           bool end) override;
 
+ protected:
+  ~TrackingSynchronizer() override;
+
+  // Update the sequence of completed phases with a new phase completion info.
+  // |now| is the current time, but can be something else in tests.
+  void RegisterPhaseCompletion(
+      ProfilerEventProto::ProfilerEvent profiling_event,
+      const base::TimeTicks& now);
+
+  // Notify |observer| about |profiler_data| received from process of type
+  // |process_type|. |now| is the current time, but can be something else in
+  // tests.
+  void SendData(const tracked_objects::ProcessDataSnapshot& profiler_data,
+                content::ProcessType process_type,
+                const base::TimeTicks& now,
+                TrackingSynchronizerObserver* observer) const;
+
  private:
   friend class base::RefCountedThreadSafe<TrackingSynchronizer>;
-  // TODO(vadimt): Remove friending TrackingSynchronizerTest_ProfilerData_Test.
-  friend class TrackingSynchronizerTest_ProfilerData_Test;
 
   class RequestContext;
 
-  ~TrackingSynchronizer() override;
-
   // Send profiler_data back to callback_object_ by calling
   // DecrementPendingProcessesAndSendData which records that we are waiting
   // for one less profiler data from renderer or browser child process for the
@@ -89,13 +107,10 @@ class TrackingSynchronizer
   int RegisterAndNotifyAllProcesses(
       const base::WeakPtr<TrackingSynchronizerObserver>& callback_object);
 
-  // Notify |observer| about |profiler_data| received from process of type
-  // |process_type|. |now| is the current time, but can be something else in
-  // tests.
-  void SendData(const tracked_objects::ProcessDataSnapshot& profiler_data,
-                content::ProcessType process_type,
-                const base::TimeTicks& now,
-                TrackingSynchronizerObserver* observer) const;
+  // Notifies all processes of a completion of a profiling phase.
+  // |profiling_event| is the event associated with the phase change.
+  void NotifyAllProcessesOfProfilingPhaseCompletion(
+      ProfilerEventProto::ProfilerEvent profiling_event);
 
   // It finds the RequestContext for the given |sequence_number| and notifies
   // the RequestContext's |callback_object_| about the |value|. This is called
@@ -127,7 +142,6 @@ class TrackingSynchronizer
   std::vector<ProfilerEventProto::ProfilerEvent>
       phase_completion_events_sequence_;
 
-  // TODO(vadimt): consider moving 2 fields below to metrics service.
   // Time of the profiling start. Used to calculate times of phase change
   // moments relative to this value.
   const base::TimeTicks start_time_;