[PPAPI] Pepper MediaStream API audio track implementation and example.

ppapi/thunk/ppb_audio_frame_api.h

Index: ppapi/thunk/ppb_audio_frame_api.h
diff --git a/ppapi/thunk/ppb_audio_frame_api.h b/ppapi/thunk/ppb_audio_frame_api.h
index 21c4d7146358e73f2824a3464fd7ff771e49417c..2e2996f7ee9305094057db7800c8d6660f99a287 100644
--- a/ppapi/thunk/ppb_audio_frame_api.h
+++ b/ppapi/thunk/ppb_audio_frame_api.h
@@ -9,6 +9,9 @@
 #include "ppapi/thunk/ppapi_thunk_export.h"
 
 namespace ppapi {
+
+union MediaStreamFrame;
+
 namespace thunk {
 
 class PPAPI_THUNK_EXPORT PPB_AudioFrame_API {
@@ -16,11 +19,17 @@ class PPAPI_THUNK_EXPORT PPB_AudioFrame_API {
   virtual ~PPB_AudioFrame_API() {}
   virtual PP_TimeDelta GetTimestamp() = 0;
   virtual void SetTimestamp(PP_TimeDelta timestamp) = 0;
+  virtual PP_AudioFrame_SampleRate GetSampleRate() = 0;
   virtual PP_AudioFrame_SampleSize GetSampleSize() = 0;
   virtual uint32_t GetNumberOfChannels() = 0;
   virtual uint32_t GetNumberOfSamples() = 0;
   virtual void* GetDataBuffer() = 0;
   virtual uint32_t GetDataBufferSize() = 0;
+
+  // Private APIs:

[yzshen1, 2014/01/29 21:28:06]

In Pepper, Private API has a different meaning. Maybe we could rephrase the
comment as "Methods used by Pepper internal implementation only."

[Peng, 2014/01/31 18:54:43]

Done.

+  virtual MediaStreamFrame* GetFrameBuffer() = 0;
+  virtual int32_t GetFrameBufferIndex() = 0;
+  virtual void Invalidate() = 0;
 };
 
 }  // namespace thunk