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

media/webm/webm_constants.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_CONSTANTS_H_
 #define MEDIA_WEBM_WEBM_CONSTANTS_H_
 
 #include "base/basictypes.h"
 
 namespace media {
 
 // WebM element IDs.
 // This is a subset of the IDs in the Matroska spec.
 // http://www.matroska.org/technical/specs/index.html
+const int kWebMIdAESSettingsCipherMode = 0x47E8;
 const int kWebMIdAspectRatioType = 0x54B3;
 const int kWebMIdAttachedFile = 0x61A7;
 const int kWebMIdAttachmentLink = 0x7446;
 const int kWebMIdAttachments = 0x1941A469;
 const int kWebMIdAudio = 0xE1;
 const int kWebMIdBitDepth = 0x6264;
 const int kWebMIdBlock = 0xA1;
 const int kWebMIdBlockAddID = 0xEE;
 const int kWebMIdBlockAdditions = 0x75A1;
 const int kWebMIdBlockAdditional = 0xA5;
@@ skipping 30 matching lines @@
 const int kWebMIdCluster = 0x1F43B675;
 const int kWebMIdCodecDecodeAll = 0xAA;
 const int kWebMIdCodecID = 0x86;
 const int kWebMIdCodecName = 0x258688;
 const int kWebMIdCodecPrivate = 0x63A2;
 const int kWebMIdCodecState = 0xA4;
 const int kWebMIdColorSpace = 0x2EB524;
 const int kWebMIdContentCompAlgo = 0x4254;
 const int kWebMIdContentCompression = 0x5034;
 const int kWebMIdContentCompSettings = 0x4255;
+const int kWebMIdContentEncAESSettings = 0x47E7;
 const int kWebMIdContentEncAlgo = 0x47E1;
 const int kWebMIdContentEncKeyID = 0x47E2;
 const int kWebMIdContentEncoding = 0x6240;
 const int kWebMIdContentEncodingOrder = 0x5031;
 const int kWebMIdContentEncodings = 0x6D80;
 const int kWebMIdContentEncodingScope = 0x5032;
 const int kWebMIdContentEncodingType = 0x5033;
 const int kWebMIdContentEncryption = 0x5035;
 const int kWebMIdContentSigAlgo = 0x47E5;
 const int kWebMIdContentSigHashAlgo = 0x47E6;
@@ skipping 115 matching lines @@
 const int kWebMIdTrackUID = 0x73C5;
 const int kWebMIdVideo = 0xE0;
 const int kWebMIdVoid = 0xEC;
 const int kWebMIdWritingApp = 0x5741;
 
 const int64 kWebMReservedId = 0x1FFFFFFF;
 const int64 kWebMUnknownSize = GG_LONGLONG(0x00FFFFFFFFFFFFFF);
 
 const uint8 kWebMFlagKeyframe = 0x80;
 
+// The size is from the WebM encrypted specification. Current encrypted WebM
+// request for comments specification is here
+// http://wiki.webmproject.org/encryption/webm-encryption-rfc
+const int kWebMHmacSize = 12;
+
 }  // namespace media
 
 #endif  // MEDIA_WEBM_WEBM_CONSTANTS_H_