Fix Bug: Video with Variable Frame Rate plays at incorrect speed.

media/filters/video_cadence_estimator.h

 // Copyright 2015 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 MEDIA_FILTERS_VIDEO_CADENCE_ESTIMATOR_H_
 #define MEDIA_FILTERS_VIDEO_CADENCE_ESTIMATOR_H_
 
 #include <vector>
 
 #include "base/time/time.h"
@@ skipping 70 matching lines @@
   // Clients should call this and then update the cadence for all frames via the
   // GetCadenceForFrame() method if the cadence changes.
   //
   // Cadence changes will not take affect until enough render intervals have
   // elapsed.  For the purposes of hysteresis, each UpdateCadenceEstimate() call
   // is assumed to elapse one |render_interval| worth of time.
   //
   // Returns true if the cadence has changed since the last call.
   bool UpdateCadenceEstimate(base::TimeDelta render_interval,
                              base::TimeDelta frame_duration,
+                             base::TimeDelta frame_duration_deviation,
                              base::TimeDelta max_acceptable_drift);
 
   // Returns true if a useful cadence was found.
   bool has_cadence() const { return !cadence_.empty(); }
 
   // Given a |frame_number|, where zero is the most recently rendered frame,
   // returns the ideal cadence for that frame.
   //
   // Note: Callers must track the base |frame_number| relative to all frames
   // rendered or removed after the first frame for which cadence is detected.
@@ skipping 45 matching lines @@
 
   // Tracks how many times cadence has switched during a given playback, used to
   // histogram the number of cadence changes in a playback.
   bool first_update_call_;
   int cadence_changes_;
 
   // The minimum amount of time allowed before a glitch occurs before confirming
   // cadence for a given render interval and frame duration.
   const base::TimeDelta minimum_time_until_max_drift_;
 
+  bool is_variable_frame_rate_;
+
   DISALLOW_COPY_AND_ASSIGN(VideoCadenceEstimator);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_FILTERS_VIDEO_CADENCE_ESTIMATOR_H_