Support configuring the audio buffer duration in the Pepper MediaStream API.

ppapi/shared_impl/media_stream_audio_track_shared.cc

Index: ppapi/shared_impl/media_stream_audio_track_shared.cc
diff --git a/ppapi/shared_impl/media_stream_audio_track_shared.cc b/ppapi/shared_impl/media_stream_audio_track_shared.cc
index ac649547d8c8bb32ac6248ef6de66033ef879641..4a9fdb7dcc05fe3ae9cc7f376bf4fa9f27665df6 100644
--- a/ppapi/shared_impl/media_stream_audio_track_shared.cc
+++ b/ppapi/shared_impl/media_stream_audio_track_shared.cc
@@ -11,6 +11,9 @@ bool MediaStreamAudioTrackShared::VerifyAttributes(
     const Attributes& attributes) {
   if (attributes.buffers < 0)
     return false;
+  if (!(attributes.duration == 0 ||
+        (attributes.duration >= 10 && attributes.duration <= 10000)))
+    return false;
   return true;
 }