Roll libvpx to r291625.

DEPS

 # This file is automatically processed to create .DEPS.git which is the file
 # that gclient uses under git.
 #
 # See http://code.google.com/p/chromium/wiki/UsingGit
 #
 # To test manually, run:
 #   python tools/deps2git/deps2git.py -o .DEPS.git -w <gclientdir>
 # where <gcliendir> is the absolute path to the directory containing the
 # .gclient file (the parent of 'src').
 #
@@ skipping 19 matching lines @@
   'nacl_trunk': 'http://src.chromium.org/native_client/trunk',
   'webkit_revision': 'f0e57d49d0f3a0e43e0db29852ef9779a98505bd',
   'chromium_git': 'https://chromium.googlesource.com',
   'chromiumos_git': 'https://chromium.googlesource.com/chromiumos',
   'pdfium_git': 'https://pdfium.googlesource.com',
   'skia_git': 'https://skia.googlesource.com',
   'boringssl_git': 'https://boringssl.googlesource.com',
   # After changing nacl_revision, run 'glient sync' and check native_client/DEPS
   # to update other nacl_*_revision's.
   'libaddressinput_revision': 'b52a2aeb63a28914850f3ed81cd7fd26ecdd4cdc', # from svn revision 333
-  'libvpx_revision': 'ace65784417788374f0b19ce5a8abd06c9ccd007',
+  'libvpx_revision': '563c46bb2d0e5d5c8b7d2c6c0c50f0283e9087de', # r291625
   'sfntly_revision': '1bdaae8fc788a5ac8936d68bf24f37d977a13dac',
   'skia_revision': '76db31a2ca11da4dd45016e964b2e49f39f3dd49',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling Skia
   # and V8 without interference from each other.
   'v8_branch': 'trunk',
   'v8_revision': 'f1a5a1dc668380a183184ee7629703846eefcfae',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling WebRTC
   # and V8 without interference from each other.
@@ skipping 721 matching lines @@
     # migration completes (let's say Sep 1 2014).
     'name': 'check_git_config',
     'pattern': '.',
     'action': [
         'python',
         'src/tools/check_git_config.py',
         '--running-as-hook',
     ],
   },
 ]