Roll src/third_party/ffmpeg/ 20d74768d..77fdc79ab (3 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 180 matching lines @@
   'src/third_party/webgl/src':
    Var('chromium_git') + '/external/khronosgroup/webgl.git' + '@' + 'a7670bc1d871a246ac10e2cd64479a3010ca3f9f',
 
   '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' + '@' +  'b2ccb9c189069d45d201c988184e9e0796b96270',
 
   'src/third_party/ffmpeg':
-   Var('chromium_git') + '/chromium/third_party/ffmpeg.git' + '@' + '20d74768dcd9886f90fe14719d3513b356b11053',
+   Var('chromium_git') + '/chromium/third_party/ffmpeg.git' + '@' + '77fdc79ab48570f5018cb4d4086909e8b7297743',
 
   'src/third_party/libjingle/source/talk':
     Var('chromium_git') + '/external/webrtc/trunk/talk.git' + '@' + 'ca22ce254a986a0b0878d27c4789dacc2eb418a5', # commit position 12581
 
   'src/third_party/usrsctp/usrsctplib':
     Var('chromium_git') + '/external/github.com/sctplab/usrsctp' + '@' + 'c60ec8b35c3fe6027d7a3faae89d1c8d7dd3ce98',
 
   'src/third_party/libsrtp':
    Var('chromium_git') + '/chromium/deps/libsrtp.git' + '@' + '720780acf8fa41c4a6ad515d0382d62f8f5195eb', # from svn revision 295151
 
@@ skipping 643 matching lines @@
                'src/build/android/download_doclava.py',
     ],
   },
   {
     # A change to a .gyp, .gypi, or to GYP itself should run the generator.
     'name': 'gyp',
     'pattern': '.',
     'action': ['python', 'src/build/gyp_chromium', '--running-as-hook'],
   },
 ]