Increase the buffer size in AudioRendererImpl to fix muted playback rate

media/audio/audio_util.h

Index: media/audio/audio_util.h
diff --git a/media/audio/audio_util.h b/media/audio/audio_util.h
index d8de4799f7fee10e95e042212ced9afc463104d9..3730c1195e4c90f1d2e01be0c07e1801298b8e2a 100644
--- a/media/audio/audio_util.h
+++ b/media/audio/audio_util.h
@@ -10,6 +10,8 @@
 #include "base/basictypes.h"
 #include "media/base/media_export.h"
 
+struct AudioParameters;
+
 namespace base {
 class SharedMemory;
 }
@@ -122,6 +124,9 @@ MEDIA_EXPORT void Crossfade(int bytes_to_crossfade, int number_of_channels,
                             int bytes_per_channel, const uint8* src,
                             uint8* dest);
 
+// Calculates a safe hardware buffer size (in number of samples) given a set
+// of audio parameters.
+MEDIA_EXPORT uint32 SelectSamplesPerPacket(int sample_rate);
 
 }  // namespace media