Code: long mkvparser::ParseElementHeader(IMkvReader* pReader, long long& pos,
                                   long long stop, long long& id,
                                   long long& size) {
  if ((stop >= 0) && (pos >= stop))
     return E_FILE_FORMAT_INVALID;
 
   long len;
 
  id = ReadUInt(pReader, pos, len);
 
   if (id < 0)
     return E_FILE_FORMAT_INVALID;
 
   pos += len;  // consume id
 
  if ((stop >= 0) && (pos >= stop))
     return E_FILE_FORMAT_INVALID;
 
   size = ReadUInt(pReader, pos, len);
 
  if (size < 0)
     return E_FILE_FORMAT_INVALID;
 
   pos += len;  // consume length of size
 
 
  if ((stop >= 0) && ((pos + size) > stop))
     return E_FILE_FORMAT_INVALID;
 
   return 0;  // success
 }

Vulnerability Type: DoS Exec Code Mem. Corr. 
CWE ID: CWE-20
Summary: libvpx in libwebm in mediaserver in Android 4.x before 4.4.4, 5.0.x before 5.0.2, 5.1.x before 5.1.1, and 6.x before 2016-06-01 allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via a crafted mkv file, aka internal bug 23167726.
Commit Message: external/libvpx/libwebm: Update snapshot

Update libwebm snapshot. This update contains security fixes from upstream.

Upstream git hash: 229f49347d19b0ca0941e072b199a242ef6c5f2b

BUG=23167726

Change-Id: Id3e140e7b31ae11294724b1ecfe2e9c83b4d4207
(cherry picked from commit d0281a15b3c6bd91756e453cc9398c5ef412d99a)
