Delivering the FIRST_NONEMPTY_PAINT phase changing event to base/

components/metrics/profiler/tracking_synchronizer.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 COMPONENTS_METRICS_PROFILER_TRACKING_SYNCHRONIZER_H_
 #define COMPONENTS_METRICS_PROFILER_TRACKING_SYNCHRONIZER_H_
 
 #include <map>
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/lazy_instance.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
+#include "base/time/tick_clock.h"
 #include "base/time/time.h"
 #include "components/metrics/proto/chrome_user_metrics_extension.pb.h"
 #include "content/public/browser/profiler_subscriber.h"
 
 // This class maintains state that is used to upload profiler data from the
 // various processes, into the browser process. Such transactions are usually
 // instigated by the browser. In general, a process will respond by gathering
 // profiler data, and transmitting the pickled profiler data. We collect the
 // data in asynchronous mode that doesn't block the UI thread.
 //
@@ skipping 10 matching lines @@
 
 class TrackingSynchronizerObserver;
 
 class TrackingSynchronizer
     : public content::ProfilerSubscriber,
       public base::RefCountedThreadSafe<TrackingSynchronizer> {
  public:
   // Construction also sets up the global singleton instance. This instance is
   // used to communicate between the IO and UI thread, and is destroyed only as
   // the main thread (browser_main) terminates, which means the IO thread has
-  // already completed, and will not need this instance any further. |now| is
-  // the current time, but can be something else in tests.
-  explicit TrackingSynchronizer(base::TimeTicks now);
+  // already completed, and will not need this instance any further.
+  // |clock| is a clock used for durations of profiling phases.
+  // TrackingSynchronizer takes ownership of this pointer.
+  explicit TrackingSynchronizer(base::TickClock* clock);

[Ilya Sherman, 2015/04/07 22:58:35]

nit: Please pass a scoped_ptr, rather than simply documenting in comments about
the ownership transfer.

[vadimt, 2015/04/08 01:09:50]

Done.

 
   // Contact all processes, and get them to upload to the browser any/all
   // changes to profiler data. It calls |callback_object|'s SetData method with
   // the data received from each sub-process.
   // This method is accessible on UI thread.
   static void FetchProfilerDataAsynchronously(
       const base::WeakPtr<TrackingSynchronizerObserver>& callback_object);
 
+  // Called when a profiling phase completes. |profiling_event| is the event
+  // that triggered the completion of the current phase, and begins a new phase.
+  static void OnProfilingPhaseCompleted(
+      ProfilerEventProto::ProfilerEvent profiling_event);
+
   // ------------------------------------------------------
   // ProfilerSubscriber methods for browser child processes
   // ------------------------------------------------------
 
   // Update the number of pending processes for the given |sequence_number|.
   // This is called on UI thread.
   void OnPendingProcesses(int sequence_number,
                           int pending_processes,
                           bool end) override;
 
+ protected:
+  ~TrackingSynchronizer() override;
+
+  // Update the sequence of completed phases with a new phase completion info.
+  void RegisterPhaseCompletion(
+      ProfilerEventProto::ProfilerEvent profiling_event);
+
+  // Notify |observer| about |profiler_data| received from process of type
+  // |process_type|.
+  void SendData(const tracked_objects::ProcessDataSnapshot& profiler_data,
+                content::ProcessType process_type,
+                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
   // given sequence number. This method is accessible on UI thread.
   void OnProfilerDataCollected(
       int sequence_number,
       const tracked_objects::ProcessDataSnapshot& profiler_data,
       content::ProcessType process_type) override;
 
   // Establish a new sequence_number_, and use it to notify all the processes of
   // the need to supply, to the browser, their tracking data. It also registers
   // |callback_object| in |outstanding_requests_| map. Return the
   // sequence_number_ that was used. This method is accessible on UI thread.
   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,
-                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
   // whenever we receive profiler data from processes. It also records that we
   // are waiting for one less profiler data from a process for the given
   // sequence number. If we have received a response from all renderers and
   // browser processes, then it calls RequestContext's DeleteIfAllDone to delete
   // the entry for sequence_number. This method is accessible on UI thread.
   void DecrementPendingProcessesAndSendData(
       int sequence_number,
@@ skipping 11 matching lines @@
   // requests. All sequence numbers used are non-negative.
   // last_used_sequence_number_ is the most recently used number (used to avoid
   // reuse for a long time).
   int last_used_sequence_number_;
 
   // Sequence of events associated with already completed profiling phases. The
   // index in the vector is the phase number. The current phase is not included.
   std::vector<ProfilerEventProto::ProfilerEvent>
       phase_completion_events_sequence_;
 
-  // TODO(vadimt): consider moving 2 fields below to metrics service.
+  // Clock for profiling phase durations.
+  const scoped_ptr<base::TickClock> clock_;
+
   // Time of the profiling start. Used to calculate times of phase change
   // moments relative to this value.
   const base::TimeTicks start_time_;
 
   // Times of starts of all profiling phases, including the current phase. The
   // index in the vector is the phase number.
   std::vector<base::TimeTicks> phase_start_times_;
 
   DISALLOW_COPY_AND_ASSIGN(TrackingSynchronizer);
 };
 
 }  // namespace metrics
 
 #endif  // COMPONENTS_METRICS_PROFILER_TRACKING_SYNCHRONIZER_H_