Switch audio synchronization from sleep() based to select() based.

content/browser/renderer_host/media/audio_sync_reader.h

Index: content/browser/renderer_host/media/audio_sync_reader.h
diff --git a/content/browser/renderer_host/media/audio_sync_reader.h b/content/browser/renderer_host/media/audio_sync_reader.h
index fdfbf81a6013ff132a5d142b8356b9dcfd7fabb4..3842f49b6ee57d8fc56f1f2e6790fe9dbdae9d9b 100644
--- a/content/browser/renderer_host/media/audio_sync_reader.h
+++ b/content/browser/renderer_host/media/audio_sync_reader.h
@@ -33,6 +33,7 @@ class AudioSyncReader : public media::AudioOutputController::SyncReader {
 
   // media::AudioOutputController::SyncReader implementations.
   virtual void UpdatePendingBytes(uint32 bytes) OVERRIDE;
+  // TODO(dalecurtis): Remove block.
   virtual int Read(bool block,
                    const media::AudioBus* source,
                    media::AudioBus* dest) OVERRIDE;
@@ -50,8 +51,9 @@ class AudioSyncReader : public media::AudioOutputController::SyncReader {
   // Indicates whether the renderer has data available for reading.
   bool DataReady();
 
-  // Blocks until DataReady() is true or a timeout expires.
-  void WaitTillDataReady();
+  // Blocks until DataReady() is true or a timeout expires.  Returns false if a
+  // timeout occurs.
+  bool WaitTillDataReady();
 
   base::SharedMemory* shared_memory_;
 
@@ -83,6 +85,14 @@ class AudioSyncReader : public media::AudioOutputController::SyncReader {
   size_t renderer_callback_count_;
   size_t renderer_missed_callback_count_;
 
+  // The maximum amount of time to wait for data from the renderer.  Calculated
+  // from the parameters given at construction.
+  const base::TimeDelta maximum_wait_time_;
+
+  // The index of the audio buffer we're expecting to be sent from the renderer;
+  // used to block with timeout for audio data.
+  uint32_t buffer_index_;
+
   DISALLOW_COPY_AND_ASSIGN(AudioSyncReader);
 };