Fire canplaythrough event at the proper time for audio/video

media/filters/dummy_demuxer.cc

Index: media/filters/dummy_demuxer.cc
diff --git a/media/filters/dummy_demuxer.cc b/media/filters/dummy_demuxer.cc
index 24307b9ef14562bdef95f6b3a353a9c9c8c2784d..095ffee762bd5362822987c3805dd272c1c3079c 100644
--- a/media/filters/dummy_demuxer.cc
+++ b/media/filters/dummy_demuxer.cc
@@ -48,6 +48,10 @@ DummyDemuxer::~DummyDemuxer() {}
 
 void DummyDemuxer::SetPreload(Preload preload) {}
 
+int DummyDemuxer::GetBitrate() {
+  return 0;
+}
+
 scoped_refptr<DemuxerStream> DummyDemuxer::GetStream(DemuxerStream::Type type) {
   return streams_[type];
 }