Support for AudioContextOptions latencyHint.

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

 /*
  * Copyright (C) 2011, Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1.  Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 10 matching lines @@
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
  * DAMAGE.
  */
 
 #ifndef DefaultAudioDestinationNode_h
 #define DefaultAudioDestinationNode_h
 
 #include "modules/webaudio/AudioDestinationNode.h"
 #include "platform/audio/AudioDestination.h"
+#include "public/platform/WebAudioLatencyHint.h"

[hongchan, 2016/12/02 17:40:12]

Do we need the actual inclusion here? I think the forward declaration below is
good enough.

[Andrew MacPherson, 2016/12/05 14:12:53]

I believe it's required due to the m_latencyHint member on the type here.

 #include <memory>
 
 namespace blink {
 
 class BaseAudioContext;
 class ExceptionState;
+class WebAudioLatencyHint;
 
 class DefaultAudioDestinationHandler final : public AudioDestinationHandler {
  public:
-  static PassRefPtr<DefaultAudioDestinationHandler> create(AudioNode&);
+  static PassRefPtr<DefaultAudioDestinationHandler> create(
+      AudioNode&,
+      const WebAudioLatencyHint&);
   ~DefaultAudioDestinationHandler() override;
 
   // AudioHandler
   void dispose() override;
   void initialize() override;
   void uninitialize() override;
   void setChannelCount(unsigned long, ExceptionState&) override;
 
   // AudioDestinationHandler
   void startRendering() override;
   void stopRendering() override;
   unsigned long maxChannelCount() const override;
+  double sampleRate() const override;
+  int framesPerBuffer() const override;
 
  private:
-  explicit DefaultAudioDestinationHandler(AudioNode&);
+  explicit DefaultAudioDestinationHandler(AudioNode&,
+                                          const WebAudioLatencyHint&);
   void createDestination();
 
   std::unique_ptr<AudioDestination> m_destination;
   String m_inputDeviceId;
   unsigned m_numberOfInputChannels;
+  const WebAudioLatencyHint m_latencyHint;
 };
 
 class DefaultAudioDestinationNode final : public AudioDestinationNode {
  public:
-  static DefaultAudioDestinationNode* create(BaseAudioContext*);
+  static DefaultAudioDestinationNode* create(BaseAudioContext*,
+                                             const WebAudioLatencyHint&);
 
  private:
-  explicit DefaultAudioDestinationNode(BaseAudioContext&);
+  explicit DefaultAudioDestinationNode(BaseAudioContext&,
+                                       const WebAudioLatencyHint&);
 };
 
 }  // namespace blink
 
 #endif  // DefaultAudioDestinationNode_h