Using native sampling rate and optimal buffer size for audio on Android.

media/audio/android/audio_manager_android.h

Index: media/audio/android/audio_manager_android.h
===================================================================
--- media/audio/android/audio_manager_android.h	(revision 200599)
+++ media/audio/android/audio_manager_android.h	(working copy)
@@ -53,6 +53,11 @@
   void RegisterHeadsetReceiver();
   void UnregisterHeadsetReceiver();
   int GetNativeOutputSampleRate();
+  int GetMinInputFrameSize(int rate, int channels);
+  int GetMinOutputFrameSize(int rate, int channels);
+  bool IsAudioLowLatencySupported();
+  int GetAudioLowLatencyFrameSize();
+  int GetOptimalOutputFrameSize(int sample_rate, int channels);
 
   // Java AudioManager instance.
   base::android::ScopedJavaGlobalRef<jobject> j_audio_manager_;