Refactoring to share MockAudioOutputStream implementations across 3 platforms

media/audio/linux/alsa_output.h

 // Copyright (c) 2009 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.
 //
 // Creates an output stream based on the ALSA PCM interface.  The current
 // implementation creates one thread per ALSA playback handle that is
 // responsible for synchronously pulling data from the audio data source.
 //
 // This output stream buffers in two places:
 //   (1) In the ALSA device
@@ skipping 47 matching lines @@
                       char bits_per_sample);
   virtual ~AlsaPCMOutputStream();
 
   // Implementation of AudioOutputStream.
   virtual bool Open(size_t packet_size);
   virtual void Close();
   virtual void Start(AudioSourceCallback* callback);
   virtual void Stop();
   virtual void SetVolume(double left_level, double right_level);
   virtual void GetVolume(double* left_level, double* right_level);
-  virtual size_t GetNumBuffers();
 
  private:
   // Closes the playback handle, reporting errors if any occur.  Returns true
   // if the device was successfully closed.
   bool CloseDevice_Locked();
 
   // Stops playback, ignoring state checks.
   void StopInternal_Locked();
 
   // Moves the stream into the error state, setting the correct internal flags.
@@ skipping 78 matching lines @@
   // FillAlsaDeviceBuffer() methods.
   bool device_write_suspended_;
 
   // Flag indicating that the resources are already cleaned.
   bool resources_released_;
 
   DISALLOW_COPY_AND_ASSIGN(AlsaPCMOutputStream);
 };
 
 #endif  // MEDIA_AUDIO_LINUX_ALSA_OUTPUT_H_