Add WebThread in AudioDestination to support AudioWorkletThread

third_party/WebKit/Source/platform/audio/AudioDestination.h

Index: third_party/WebKit/Source/platform/audio/AudioDestination.h
diff --git a/third_party/WebKit/Source/platform/audio/AudioDestination.h b/third_party/WebKit/Source/platform/audio/AudioDestination.h
index 6bf30f33af2608473c36eb0b59c957efea71d48b..493a319503462498676016b943f6bf2ed05eee26 100644
--- a/third_party/WebKit/Source/platform/audio/AudioDestination.h
+++ b/third_party/WebKit/Source/platform/audio/AudioDestination.h
@@ -43,6 +43,7 @@ namespace blink {
 class PushPullFIFO;
 class SecurityOrigin;
 class WebAudioLatencyHint;
+class WebThread;
 
 // The AudioDestination class is an audio sink interface between the media
 // renderer and the Blink's WebAudio module. It has a FIFO to adapt the
@@ -76,7 +77,13 @@ class PLATFORM_EXPORT AudioDestination : public WebAudioDevice::RenderCallback {
   virtual void Start();
   virtual void Stop();
 
+  void RequestRenderOnWebThread(size_t numberOfFrames,
+                                double delay,
+                                double delayTimestamp,
+                                size_t priorFramesSkipped);

[o1ka, 2017/04/13 08:36:53]

Should these params also be renamed with a new style?

[hongchan, 2017/04/14 16:31:48]

Done.

+
   size_t CallbackBufferSize() const { return callback_buffer_size_; }
+
   bool IsPlaying() { return is_playing_; }
 
   double SampleRate() const { return web_audio_device_->SampleRate(); }
@@ -85,7 +92,7 @@ class PLATFORM_EXPORT AudioDestination : public WebAudioDevice::RenderCallback {
   // hardware.
   int FramesPerBuffer() const { return web_audio_device_->FramesPerBuffer(); }
 
-  // The information from the actual audio hardware. (via Platform::current)
+  // The information from the actual audio hardware. (via Platform::Current())
   static float HardwareSampleRate();
   static unsigned long MaxChannelCount();
 
@@ -95,27 +102,24 @@ class PLATFORM_EXPORT AudioDestination : public WebAudioDevice::RenderCallback {
   size_t callback_buffer_size_;
   bool is_playing_;
 
-  // The render callback function of WebAudio engine. (i.e. DestinationNode)
-  AudioIOCallback& callback_;
+  // WebThread for WebAudio rendering.
+  std::unique_ptr<WebThread> rendering_thread_;
 
   // To pass the data from FIFO to the audio device callback.
   RefPtr<AudioBus> output_bus_;
 
-  // To push the rendered result from WebAudio graph into the FIFO.
-  RefPtr<AudioBus> render_bus_;
-
   // Resolves the buffer size mismatch between the WebAudio engine and
   // the callback function from the actual audio device.
   std::unique_ptr<PushPullFIFO> fifo_;
 
-  size_t frames_elapsed_;
-  AudioIOPosition output_position_;
-  base::TimeTicks output_position_received_timestamp_;
-
   // Check if the buffer size chosen by the WebAudioDevice is too large.
   bool CheckBufferSize();
 
   size_t HardwareBufferSize();
+
+  bool IsRenderingThread();
+
+  size_t frames_elapsed_;
 };
 
 }  // namespace blink