DEPS: update ffmepg to current version

Includes:
r74188 | evan@chromium.org | 2011-02-08 14:19:20 -0800 (Tue, 08 Feb 2011) | 2 lines
linux: don't warn about libavformat using its own deprecated APIs

r72929 | fbarchard@chromium.org | 2011-01-27 21:07:20 -0800 (Thu, 27 Jan 2011) | 5 lines
remove patch 02 mov in ffmpeg and cleanup patch 14

Review URL: http://codereview.chromium.org/6456004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@74207 0039d316-1c4b-4281-b951-d872f2087c98

DEPS

@@ -10,7 +10,7 @@ vars = {
   "nacl_revision": "4270",
   "libjingle_revision": "50",
   "libvpx_revision": "65287",
-  "ffmpeg_revision": "71842",
+  "ffmpeg_revision": "74188",
   "skia_revision": "772",
 }