MSE: Notify Blink SourceBuffer on init segment received

media/blink/websourcebuffer_impl.h

Index: media/blink/websourcebuffer_impl.h
diff --git a/media/blink/websourcebuffer_impl.h b/media/blink/websourcebuffer_impl.h
index e9381788adb30072419ce930c434b264e59d6db4..96e37b609541715270177231362e8e975b3bb7b2 100644
--- a/media/blink/websourcebuffer_impl.h
+++ b/media/blink/websourcebuffer_impl.h
@@ -21,6 +21,7 @@ class WebSourceBufferImpl : public blink::WebSourceBuffer {
   virtual ~WebSourceBufferImpl();
 
   // blink::WebSourceBuffer implementation.
+  virtual void setClient(blink::WebSourceBufferClient* client);
   virtual bool setMode(AppendMode mode);
   virtual blink::WebTimeRanges buffered();
   virtual void append(
@@ -35,9 +36,15 @@ class WebSourceBufferImpl : public blink::WebSourceBuffer {
   virtual void removedFromMediaSource();
 
  private:
+  // Demuxer callback handler to process an initialization segment received
+  // during an append() call.
+  void InitSegmentReceived();
+
   std::string id_;
   ChunkDemuxer* demuxer_;  // Owned by WebMediaPlayerImpl.
 
+  blink::WebSourceBufferClient* client_;
+
   // Controls the offset applied to timestamps when processing appended media
   // segments. It is initially 0, which indicates that no offset is being
   // applied. Both setTimestampOffset() and append() may update this value.