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

media/webm/webm_cluster_parser.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MEDIA_WEBM_WEBM_CLUSTER_PARSER_H_
 #define MEDIA_WEBM_WEBM_CLUSTER_PARSER_H_
 
 #include <deque>
 #include <string>
 
 #include "base/memory/scoped_ptr.h"
 #include "media/base/media_export.h"
 #include "media/base/stream_parser_buffer.h"
 #include "media/webm/webm_parser.h"
 
 namespace media {
 
 class MEDIA_EXPORT WebMClusterParser : public WebMParserClient {
  public:
   typedef std::deque<scoped_refptr<StreamParserBuffer> > BufferQueue;
 
+  // Size is defined by the WebM encryption specification.
+  // http://wiki.webmproject.org/encryption/webm-encryption-rfc
+  static const int kIvSize = 8;
+
   WebMClusterParser(int64 timecode_scale,
                     int audio_track_num,
                     int video_track_num,
                     const uint8* video_encryption_key_id,
                     int video_encryption_key_id_size);
   virtual ~WebMClusterParser();
 
   // Resets the parser state so it can accept a new cluster.
   void Reset();
 
@@ skipping 55 matching lines @@
 
   Track audio_;
   Track video_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(WebMClusterParser);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_WEBM_WEBM_CLUSTER_PARSER_H_