Update DEPS with new third party library openmax_dl.

DEPS

 # When adding a new dependency, please update the top-level .gitignore file
 # to list the dependency's destination directory.
 
 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",
@@ skipping 276 matching lines @@
   "src/third_party/pyftpdlib/src":
     (Var("googlecode_url") % "pyftpdlib") + "/trunk@977",
 
   "src/third_party/scons-2.0.1":
     Var("nacl_trunk") + "/src/third_party/scons-2.0.1@" +
         Var("nacl_tools_revision"),
 
   "src/third_party/webrtc":
     (Var("googlecode_url") % "webrtc") + "/stable/webrtc@" + Var("webrtc_revision"),
 
+  "src/third_party/openmax_dl":
+    (Var("googlecode_url") % "webrtc") + "/deps/third_party/openmax@3720",
+
   "src/third_party/jsoncpp/source/include":
     (Var("sourceforge_url") % {"repo": "jsoncpp"}) +
         "/trunk/jsoncpp/include@" + Var("jsoncpp_revision"),
 
   "src/third_party/jsoncpp/source/src/lib_json":
     (Var("sourceforge_url") % {"repo": "jsoncpp"}) +
         "/trunk/jsoncpp/src/lib_json@" + Var("jsoncpp_revision"),
 
   "src/third_party/libyuv":
     (Var("googlecode_url") % "libyuv") + "/trunk@618",
@@ skipping 389 matching lines @@
     # A change to a .gyp, .gypi, or to GYP itself should run the generator.
     "pattern": ".",
     "action": ["python", "src/build/gyp_chromium"],
   },
   {
     # Check for landmines (reasons to clobber the build).
     "pattern": ".",
     "action": ["python", "src/build/landmines.py"],
   },
 ]