cc: Improve frame/commit accounting

cc/frame_rate_counter.h

 // Copyright 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 CCFrameRateCounter_h
 #define CCFrameRateCounter_h
 
+#include "CCRenderingStats.h"
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/time.h"
 
 namespace cc {
 
 // This class maintains a history of timestamps, and provides functionality to
 // intelligently compute average frames per second (and standard deviation).
 class CCFrameRateCounter {
 public:
     static scoped_ptr<CCFrameRateCounter> create();
 
+    void setTimebaseAndInterval(base::TimeTicks timebase, base::TimeDelta interval);
+
     void markBeginningOfFrame(base::TimeTicks timestamp);
     void markEndOfFrame();
-    int currentFrameNumber() const { return m_currentFrameNumber; }
+    int64_t currentFrameNumber() const { return m_currentFrameNumber; }
     void getAverageFPSAndStandardDeviation(double& averageFPS, double& standardDeviation) const;
     int timeStampHistorySize() const { return kTimeStampHistorySize; }
 
     // n = 0 returns the oldest frame retained in the history,
     // while n = timeStampHistorySize() - 1 returns the timestamp most recent frame.
     base::TimeTicks timeStampOfRecentFrame(int n);
 
     // This is a heuristic that can be used to ignore frames in a reasonable way. Returns
     // true if the given frame interval is too fast or too slow, based on constant thresholds.
     bool isBadFrameInterval(base::TimeDelta intervalBetweenConsecutiveFrames) const;
 
-    int droppedFrameCount() const { return m_droppedFrameCount; }
+    void renderingStats(CCRenderingStats* stats) const;
 
 private:
     CCFrameRateCounter();
 
     base::TimeDelta frameInterval(int frameNumber) const;
     int frameIndex(int frameNumber) const;
     bool isBadFrame(int frameNumber) const;
+    int64_t currentVsyncCount(base::TimeTicks now) const;
+
+    static const int kTimeStampHistorySize = 120;
+
+    base::TimeTicks m_timeStampHistory[kTimeStampHistorySize];
 
     // Two thresholds (measured in seconds) that describe what is considered to be a "no-op frame" that should not be counted.
     // - if the frame is too fast, then given our compositor implementation, the frame probably was a no-op and did not draw.
     // - if the frame is too slow, then there is probably not animating content, so we should not pollute the average.
-    static const double kFrameTooFast;
-    static const double kFrameTooSlow;
+    double m_frameTooFastSeconds;
+    double m_frameTooSlowSeconds;
 
-    // If a frame takes longer than this threshold (measured in seconds) then we
-    // (naively) assume that it missed a screen refresh; that is, we dropped a frame.
-    // FIXME: Determine this threshold based on monitor refresh rate, crbug.com/138642.
-    static const double kDroppedFrameTime;
-
-    static const int kTimeStampHistorySize = 120;
-
-    int m_currentFrameNumber;
-    base::TimeTicks m_timeStampHistory[kTimeStampHistorySize];
-
-    int m_droppedFrameCount;
+    int64_t m_vsyncCount;
+    int64_t m_currentFrameNumber;
+    bool m_active;
+    base::TimeTicks m_activeTimestamp;
+    base::TimeTicks m_intervalChangedTime;
+    base::TimeDelta m_interval;
 
     DISALLOW_COPY_AND_ASSIGN(CCFrameRateCounter);
 };
 
 }  // namespace cc
 
 #endif