Remove buffer duration calculation from WebMClusterParser and update SourceBufferStream accordingly

media/webm/webm_cluster_parser.h

Index: media/webm/webm_cluster_parser.h
diff --git a/media/webm/webm_cluster_parser.h b/media/webm/webm_cluster_parser.h
index ea76d30370f9f13e37e19e23cdbfcdb9b98ea108..f98b6ccb2f355215c7e7023a5adf4fba9bb28a2c 100644
--- a/media/webm/webm_cluster_parser.h
+++ b/media/webm/webm_cluster_parser.h
@@ -59,17 +59,11 @@ class MEDIA_EXPORT WebMClusterParser : public WebMParserClient {
     void ClearBufferQueue();
 
    private:
-    // Sets the duration of all the buffers in |delayed_buffers_|
-    // and then moves these buffers into |buffers_|. |delayed_buffers_|
-    // is empty when this call returns.
-    void SetDelayedBufferDurations(base::TimeDelta duration);
-
     // Adds the buffer to |buffers_|. |buffer| must have its duration set.
     void AddToBufferQueue(const scoped_refptr<StreamParserBuffer>& buffer);
 
     int track_num_;
     BufferQueue buffers_;
-    BufferQueue delayed_buffers_;
   };
 
   // WebMParserClient methods.