Some fixups for AudioController and unit tests

media/audio/audio_controller.h

 // Copyright (c) 2010 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_AUDIO_CONTROLLER_H_
 #define MEDIA_AUDIO_AUDIO_CONTROLLER_H_
 
 #include "base/lock.h"
 #include "base/ref_counted.h"
 #include "base/scoped_ptr.h"
@@ skipping 89 matching lines @@
   // Factory method for creating an AudioController, returns NULL if failed.
   // If successful, an audio controller thread is created. The audio device
   // will be created on the audio controller thread and when that is done
   // event handler will receive a OnCreated() call.
   static scoped_refptr<AudioController> Create(
       EventHandler* event_handler,
       AudioManager::Format format,    // Format of the stream.
       int channels,                   // Number of channels.
       int sample_rate,                // Sampling frequency/rate.
       int bits_per_sample,            // Number of bits per sample.
-      int hardware_buffer_size,       // Size of the hardware buffer.
+      uint32 hardware_buffer_size,    // Size of the hardware buffer.
 
       // Soft limit for buffer capacity in this controller. This parameter
       // is used only in regular latency mode.
       uint32 buffer_capacity);
 
   // Factory method for creating a low latency audio stream.
   static scoped_refptr<AudioController> CreateLowLatency(
       EventHandler* event_handler,
       AudioManager::Format format,    // Format of the stream.
       int channels,                   // Number of channels.
       int sample_rate,                // Sampling frequency/rate.
       int bits_per_sample,            // Number of bits per sample.
-      int hardware_buffer_size,       // Size of the hardware buffer.
+      uint32 hardware_buffer_size,    // Size of the hardware buffer.
 
       // External synchronous reader for audio controller.
       SyncReader* sync_reader);
 
   // Methods to control playback of the stream.
 
   // Starts the playback of this audio output stream.
   void Play();
 
   // Pause this audio output stream.
   void Pause();
 
   // Discard all audio data buffered in this output stream. This method only
   // has effect when the stream is paused.
   void Flush();
 
   // Closes the audio output stream and shutdown the audio controller thread.
   // This method returns only after all operations are completed. This
   // controller cannot be used after this method is called.
+  //
+  // It is safe to call this method more than once. Calls after the first one
+  // will have no effect.
   void Close();
 
   // Sets the volume of the audio output stream.
   void SetVolume(double volume);
 
   // Enqueue audio |data| into the controller. This method is used only in
   // the regular latency mode and it is illegal to call this method when
   // SyncReader is present.
   void EnqueueData(const uint8* data, uint32 size);
 
+  bool LowLatencyMode() const { return sync_reader_ != NULL; }
+
   ///////////////////////////////////////////////////////////////////////////
   // AudioSourceCallback methods.
   virtual uint32 OnMoreData(AudioOutputStream* stream, void* dest,
                             uint32 max_size, uint32 pending_bytes);
   virtual void OnClose(AudioOutputStream* stream);
   virtual void OnError(AudioOutputStream* stream, int code);
 
  private:
   AudioController(EventHandler* handler,
                   uint32 capacity, SyncReader* sync_reader);
 
   // The following methods are executed on the audio controller thread.
   void DoCreate(AudioManager::Format format, int channels,
                 int sample_rate, int bits_per_sample,
-                int hardware_buffer_size);
+                uint32 hardware_buffer_size);
   void DoPlay();
   void DoPause();
   void DoFlush();
   void DoClose();
   void DoSetVolume(double volume);
   void DoReportError(int code);
 
   // Helper method to submit a OnMoreData() call to the event handler.
   void SubmitOnMoreData_Locked();
 
@@ skipping 18 matching lines @@
 
   // The audio controller thread that this object runs on.
   base::Thread thread_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioController);
 };
 
 }  // namespace media
 
 #endif  //  MEDIA_AUDIO_AUDIO_CONTROLLER_H_