Support for AudioContextOptions latencyHint.

third_party/WebKit/Source/modules/webaudio/AudioDestinationNode.h

Index: third_party/WebKit/Source/modules/webaudio/AudioDestinationNode.h
diff --git a/third_party/WebKit/Source/modules/webaudio/AudioDestinationNode.h b/third_party/WebKit/Source/modules/webaudio/AudioDestinationNode.h
index 1aa09a97046d2d4f0c96a0e752069827e3798eba..aa14f9893d9168d7f7b89e0560124b139328df00 100644
--- a/third_party/WebKit/Source/modules/webaudio/AudioDestinationNode.h
+++ b/third_party/WebKit/Source/modules/webaudio/AudioDestinationNode.h
@@ -39,7 +39,7 @@ class BaseAudioContext;
 
 class AudioDestinationHandler : public AudioHandler, public AudioIOCallback {
  public:
-  AudioDestinationHandler(AudioNode&, float sampleRate);
+  AudioDestinationHandler(AudioNode&);
   ~AudioDestinationHandler() override;
 
   // AudioHandler
@@ -68,6 +68,10 @@ class AudioDestinationHandler : public AudioHandler, public AudioIOCallback {
 
   // Returns the rendering callback buffer size.
   virtual size_t callbackBufferSize() const = 0;
+  virtual double sampleRate() const = 0;
+
+  // Returns the audio buffer size in frames used by the AudioContext.
+  virtual int framesPerBuffer() const = 0;
 
  protected:
   // LocalAudioInputProvider allows us to expose an AudioSourceProvider for