Introducing phased profiling framework

chrome/browser/metrics/chrome_metrics_service_client.h

 // Copyright 2014 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_CHROME_METRICS_SERVICE_CLIENT_H_
 #define CHROME_BROWSER_METRICS_CHROME_METRICS_SERVICE_CLIENT_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 76 matching lines @@
   // Called after the Plugin init task has been completed that continues the
   // init task by launching a task to gather Google Update statistics.
   void OnInitTaskGotPluginInfo();
 
   // Called after GoogleUpdate init task has been completed that continues the
   // init task by loading profiler data.
   void OnInitTaskGotGoogleUpdateData();
 
   // TrackingSynchronizerObserver:
   void ReceivedProfilerData(
-      const tracked_objects::ProcessDataSnapshot& process_data,
-      int process_type) override;
+      const tracked_objects::ProcessDataPhaseSnapshot& process_data_phase,
+      base::ProcessId process_id,
+      content::ProcessType process_type,
+      int profiling_phase,
+      const base::TimeDelta& profiling_phase_start,

[dcheng, 2015/03/27 08:36:36]

TimeDelta is typically passed by value:
https://code.google.com/p/chromium/codesearch#chromium/src/base/time/time.h&l=20

+      const base::TimeDelta& profiling_phase_finish,
+      const metrics::ProfilerEvents& past_profiler_events) override;
   void FinishedReceivingProfilerData() override;
 
   // Callbacks for various stages of final log info collection. Do not call
   // these directly.
   void OnMemoryDetailCollectionDone();
   void OnHistogramSynchronizationDone();
 
   // Records metrics about the switches present on the command line.
   void RecordCommandLineMetrics();
 
@@ skipping 61 matching lines @@
   // The MemoryGrowthTracker instance that tracks memory usage growth in
   // MemoryDetails.
   MemoryGrowthTracker memory_growth_tracker_;
 
   base::WeakPtrFactory<ChromeMetricsServiceClient> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ChromeMetricsServiceClient);
 };
 
 #endif  // CHROME_BROWSER_METRICS_CHROME_METRICS_SERVICE_CLIENT_H_