Updating FFmpeg to r105642.

DEPS

 vars = {
   # Use this googlecode_url variable only if there is an internal mirror for it.
   # If you do not know, use the full path while defining your new deps entry.
   "googlecode_url": "http://%s.googlecode.com/svn",
   "webkit_trunk": "http://svn.webkit.org/repository/webkit/trunk",
   "nacl_trunk": "http://src.chromium.org/native_client/trunk",
   "webkit_revision": "97501",
   "chromium_git": "http://git.chromium.org/git",
   "swig_revision": "69281",
   "nacl_revision": "6909",
   # After changing nacl_revision, run 'glient sync' and check native_client/DEPS
   # to update other nacl_*_revision's.
   # TODO(brettw) We should use the "From" syntax to avoid hardcoding the
   # revisions here, but it makes checkdeps confused. We should fix checkdeps.
   "nacl_tools_revision": "6504",  # native_client/DEPS: tools_rev
 
   # These hashes need to be updated when nacl_toolchain_revision is changed.
   # After changing nacl_toolchain_revision, run 'gclient runhooks' to get the
   # new values.
   "nacl_toolchain_mac_x86_newlib_hash":
       "280ecee659ff804d5eeca8964c31545b0d68d9c8",
   "nacl_toolchain_win_x86_newlib_hash":
       "7730f4515c745c0c012df4a1080be9a46ffcda47",
   "nacl_toolchain_linux_x86_newlib_hash":
       "596aa5b812ec4b24160ed7ce55b3fd141f929fbf",
   "nacl_toolchain_revision": "6757",
 
   "libjingle_revision": "85",
   "libvpx_revision": "103347",
-  "ffmpeg_revision": "105596",
+  "ffmpeg_revision": "105642",
   "sfntly_revision": "98",
   "skia_revision": "2478",
   "v8_revision": "9442",
   "webrtc_revision": "711",
 
   # Note: On most bots, clang is not checked out via DEPS but by
   # tools/clang/scripts/update.sh. The script reads this line here.
   # Do NOT CHANGE this if you don't know what you're doing -- see
   # http://code.google.com/p/chromium/wiki/UpdatingClang
   "clang_revision": "140930",
@@ skipping 393 matching lines @@
     # which takes ~20s, but clang speeds up builds by more than 20s.
     "pattern": ".",
     "action": ["python", "src/tools/clang/scripts/update.py", "--mac-only"],
   },
   {
     # A change to a .gyp, .gypi, or to GYP itself should run the generator.
     "pattern": ".",
     "action": ["python", "src/build/gyp_chromium"],
   },
 ]