Roll ffmpeg for M47.

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 171 matching lines @@
   'src/third_party/webgl/src':
    Var('chromium_git') + '/external/khronosgroup/webgl.git' + '@' + 'a62453dbe975574d6b0550d3ef87a7e279ae86a1',
 
   'src/third_party/webdriver/pylib':
     Var('chromium_git') + '/external/selenium/py.git' + '@' + '5fd78261a75fe08d27ca4835fb6c5ce4b42275bd',
 
   'src/third_party/libvpx':
    Var('chromium_git') + '/chromium/deps/libvpx.git' + '@' +  Var('libvpx_revision'),
 
   'src/third_party/ffmpeg':
-   Var('chromium_git') + '/chromium/third_party/ffmpeg.git' + '@' + '67cde45fbfa5145bd7ebfe0fb811ae7a80902d43',
+   Var('chromium_git') + '/chromium/third_party/ffmpeg.git' + '@' + '382b031ebab06b25df0708dd44aafad235657d2c',
 
   'src/third_party/libjingle/source/talk':
     Var('chromium_git') + '/external/webrtc/trunk/talk.git' + '@' + '15e5120c8fa279eaaf113a638288a002172b6abb', # commit position 9991
 
   'src/third_party/usrsctp/usrsctplib':
     Var('chromium_git') + '/external/usrsctplib.git' + '@' + '36444a999739e9e408f8f587cb4c3ffeef2e50ac', # from svn revision 9215
 
   'src/third_party/libsrtp':
    Var('chromium_git') + '/chromium/deps/libsrtp.git' + '@' + '502e81a238a864cfce774d4de3893810629bf227', # from svn revision 295151
 
@@ skipping 600 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',
     ],
   },
 ]