Add support for encrypted WebM files as defined in the RFC.

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 159fd380cf877234e6dcf9199fbc73a6794c405c..5a42f8b5096a95c6586b417bd119dd5f9c9b2e2f 100644
--- a/media/webm/webm_cluster_parser.h
+++ b/media/webm/webm_cluster_parser.h
@@ -19,6 +19,10 @@ class MEDIA_EXPORT WebMClusterParser : public WebMParserClient {
  public:
   typedef std::deque<scoped_refptr<StreamParserBuffer> > BufferQueue;
 
+  // The sizes are from the WebM encrypted specification.

[xhwang, 2012/06/06 20:54:06]

Do we have a public link to the spec to post here? 

[fgalligan1, 2012/06/08 21:02:38]

Done.

+  static const int kIntegrityCheckSize = 12;
+  static const int kIVSize = 8;

[xhwang, 2012/06/06 20:54:06]

s/kIVSize/kIvSize

[fgalligan1, 2012/06/08 21:02:38]

Done.

+
   WebMClusterParser(int64 timecode_scale,
                     int audio_track_num,
                     int video_track_num,