Fix accumulation error with front_timestamp, move test only code.

media/filters/audio_clock.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 MEDIA_FILTERS_AUDIO_CLOCK_H_
 #define MEDIA_FILTERS_AUDIO_CLOCK_H_
 
 #include <deque>
 
 #include "base/time/time.h"
@@ skipping 77 matching lines @@
   //                                             1000 + 500 + 250 = 1750 ms.
   base::TimeDelta front_timestamp() const { return front_timestamp_; }
   base::TimeDelta back_timestamp() const { return back_timestamp_; }
 
   // Returns the amount of wall time until |timestamp| will be played by the
   // audio hardware.
   //
   // |timestamp| must be within front_timestamp() and back_timestamp().
   base::TimeDelta TimeUntilPlayback(base::TimeDelta timestamp) const;
 
-  // Returns the amount of contiguous media time buffered at the head of the
-  // audio hardware buffer. Silence introduced into the audio hardware buffer is
-  // treated as a break in media time.
-  base::TimeDelta contiguous_audio_data_buffered() const {
-    return contiguous_audio_data_buffered_;
-  }
-
-  // Same as above, but also treats changes in playback rate as a break in media
-  // time.
-  base::TimeDelta contiguous_audio_data_buffered_at_same_rate() const {
-    return contiguous_audio_data_buffered_at_same_rate_;
-  }
+  void ContiguousAudioDataBufferedForTesting(
+      base::TimeDelta* total,
+      base::TimeDelta* same_rate_total) const;
 
  private:
   // Even with a ridiculously high sample rate of 256kHz, using 64 bits will
   // permit tracking up to 416999965 days worth of time (that's 1141 millenia).
   //
   // 32 bits on the other hand would top out at measly 2 hours and 20 minutes.
   struct AudioData {
     AudioData(int64_t frames, double playback_rate);
 
     int64_t frames;
     double playback_rate;
   };
 
   // Helpers for operating on |buffered_|.
   void PushBufferedAudioData(int64_t frames, double playback_rate);
   void PopBufferedAudioData(int64_t frames);
-  base::TimeDelta ComputeBufferedMediaTime(int64_t frames) const;
+  base::TimeDelta ComputeBufferedMediaDuration() const;
 
   const base::TimeDelta start_timestamp_;
   const double microseconds_per_frame_;
 
   std::deque<AudioData> buffered_;
   int64_t total_buffered_frames_;
 
   base::TimeDelta front_timestamp_;
   base::TimeDelta back_timestamp_;
 
-  // Cached results of last call to WroteAudio().
-  base::TimeDelta contiguous_audio_data_buffered_;
-  base::TimeDelta contiguous_audio_data_buffered_at_same_rate_;
-
   DISALLOW_COPY_AND_ASSIGN(AudioClock);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_FILTERS_AUDIO_CLOCK_H_