Fix incorrect opus seek preroll and flaky pre-skip removal.

media/audio/clockless_audio_sink.h

 // Copyright 2013 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_AUDIO_CLOCKLESS_AUDIO_SINK_H_
 #define MEDIA_AUDIO_CLOCKLESS_AUDIO_SINK_H_
 
 #include <string>
 
 #include "base/memory/scoped_ptr.h"
@@ skipping 23 matching lines @@
   void Pause() override;
   void Play() override;
   bool SetVolume(double volume) override;
   void SwitchOutputDevice(const std::string& device_id,
                           const GURL& security_origin,
                           const SwitchOutputDeviceCB& callback) override;
 
   // Returns the time taken to consume all the audio.
   base::TimeDelta render_time() { return playback_time_; }
 
+  // Enables audio frame hashing.  Must be called prior to Initialize().
+  void StartAudioHashForTesting();
+
+  // Returns the hash of all audio frames seen since construction.
+  std::string GetAudioHashForTesting();
+
  protected:
   ~ClocklessAudioSink() override;
 
  private:
   scoped_ptr<ClocklessAudioSinkThread> thread_;
   bool initialized_;
   bool playing_;
+  bool hashing_;
 
   // Time taken in last set of Render() calls.
   base::TimeDelta playback_time_;
 
   DISALLOW_COPY_AND_ASSIGN(ClocklessAudioSink);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_CLOCKLESS_AUDIO_SINK_H_