Roll ffmpeg 136643:137006; only change is:

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",
   "sourceforge_url": "http://%(repo)s.svn.sourceforge.net/svnroot/%(repo)s",
   "webkit_trunk": "http://svn.webkit.org/repository/webkit/trunk",
   "nacl_trunk": "http://src.chromium.org/native_client/trunk",
   "webkit_revision": "116816",
   "chromium_git": "http://git.chromium.org/git",
   "swig_revision": "69281",
@@ skipping 30 matching lines @@
   "nacl_toolchain_revision": "8428",
   "pnacl_toolchain_revision": "8428",
 
   "libjingle_revision": "136",
   "libphonenumber_revision": "425",
   "libvpx_revision": "134182",
   "lss_revision": "9",
 
   # These two FFmpeg variables must be updated together.  One is used for SVN
   # checkouts and the other for Git checkouts.
-  "ffmpeg_revision": "136643",
-  "ffmpeg_hash": "5938434ce9f24585e3f1ee4016f85ac3e837ee57",
+  "ffmpeg_revision": "137006",
+  "ffmpeg_hash": "4ece657f9dad6a37e7b7e3584eb8887aad4dc499",
 
   "sfntly_revision": "128",
   "skia_revision": "3902",
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling Skia
   # and V8 without interference from each other.
   "v8_revision": "11520",
   "webrtc_revision": "2180",
   "jsoncpp_revision": "248",
   "nss_revision": "136057",
@@ skipping 475 matching lines @@
     "pattern": ".",
     "action": ["python", "src/build/util/lastchange.py",
                "-o", "src/build/util/LASTCHANGE"],
   },
   {
     # A change to a .gyp, .gypi, or to GYP itself should run the generator.
     "pattern": ".",
     "action": ["python", "src/build/gyp_chromium"],
   },
 ]