Roll src/third_party/libvpx/source/libvpx/ 9aa083d16..afd869308 (18 commits).

DEPS

 # This file is used to manage the dependencies of the Chromium src repo. It is
 # used by gclient to determine what version of each dependency to check out, and
 # where.
 #
 # For more information, please refer to the official documentation:
 #   https://sites.google.com/a/chromium.org/dev/developers/how-tos/get-the-code
 #
 # When adding a new dependency, please update the top-level .gitignore file
 # to list the dependency's destination directory.
 #
@@ skipping 164 matching lines @@
   'src/third_party/bidichecker':
     Var('chromium_git') + '/external/bidichecker/lib.git' + '@' + '97f2aa645b74c28c57eca56992235c79850fa9e0',
 
   'src/third_party/webgl/src':
    Var('chromium_git') + '/external/khronosgroup/webgl.git' + '@' + '1012e1f8baea808f3bc9fcef945d66b5f740c32b',
 
   'src/third_party/webdriver/pylib':
     Var('chromium_git') + '/external/selenium/py.git' + '@' + '5fd78261a75fe08d27ca4835fb6c5ce4b42275bd',
 
   'src/third_party/libvpx/source/libvpx':
-   Var('chromium_git') + '/webm/libvpx.git' + '@' +  '9aa083d164e0d39086aa0c83f0d1a0d0f0d1ba61',
+   Var('chromium_git') + '/webm/libvpx.git' + '@' +  'afd869308ef4283c5a2b5e530b1f28cb9c596604',
 
   'src/third_party/ffmpeg':
    Var('chromium_git') + '/chromium/third_party/ffmpeg.git' + '@' + 'beef68513861e11156899b1f763097c31808c418',
 
   'src/third_party/libjingle/source/talk':
     Var('chromium_git') + '/external/webrtc/trunk/talk.git' + '@' + '74207eb9bd0531549670b56d662b1e02658bf529', # commit position 12032
 
   'src/third_party/usrsctp/usrsctplib':
     Var('chromium_git') + '/external/github.com/sctplab/usrsctp' + '@' + 'c60ec8b35c3fe6027d7a3faae89d1c8d7dd3ce98',
 
@@ skipping 639 matching lines @@
     'pattern': '\\.sha1',
     'action': ['python', 'src/third_party/instrumented_libraries/scripts/download_binaries.py'],
   },
   {
     # A change to a .gyp, .gypi, or to GYP itself should run the generator.
     'name': 'gyp',
     'pattern': '.',
     'action': ['python', 'src/build/gyp_chromium'],
   },
 ]