libvpx: Pull from upstream

source/libvpx/third_party/libwebm/webmids.hpp

 // Copyright (c) 2012 The WebM project authors. All Rights Reserved.
 //
 // Use of this source code is governed by a BSD-style license
 // that can be found in the LICENSE file in the root of the source
 // tree. An additional intellectual property rights grant can be found
 // in the file PATENTS.  All contributing project authors may
 // be found in the AUTHORS file in the root of the source tree.
 
 #ifndef WEBMIDS_HPP
 #define WEBMIDS_HPP
@@ skipping 115 matching lines @@
   kMkvChapters = 0x1043A770,
   kMkvEditionEntry = 0x45B9,
   kMkvChapterAtom = 0xB6,
   kMkvChapterUID = 0x73C4,
   kMkvChapterStringUID = 0x5654,
   kMkvChapterTimeStart = 0x91,
   kMkvChapterTimeEnd = 0x92,
   kMkvChapterDisplay = 0x80,
   kMkvChapString = 0x85,
   kMkvChapLanguage = 0x437C,
-  kMkvChapCountry = 0x437E
+  kMkvChapCountry = 0x437E,
+  // Tags
+  kMkvTags = 0x1254C367,
+  kMkvTag = 0x7373,
+  kMkvSimpleTag = 0x67C8,
+  kMkvTagName = 0x45A3,
+  kMkvTagString = 0x4487
 };
 
 }  // end namespace mkvmuxer
 
 #endif  // WEBMIDS_HPP