Code: long long mkvparser::UnserializeUInt(IMkvReader* pReader, long long pos,
                                     long long size) {
  assert(pReader);
  assert(pos >= 0);
  if ((size <= 0) || (size > 8))
     return E_FILE_FORMAT_INVALID;
 
   long long result = 0;

 for (long long i = 0; i < size; ++i) {
 unsigned char b;

 const long status = pReader->Read(pos, 1, &b);

 if (status < 0)
 return status;

    result <<= 8;
    result |= b;

 ++pos;
 }


   return result;
 }

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)
