Roll libvpx 248011:251580

DEPS

 # This file is automatically processed to create .DEPS.git which is the file
 # that gclient uses under git.
 #
 # See http://code.google.com/p/chromium/wiki/UsingGit
 #
 # To test manually, run:
 #   python tools/deps2git/deps2git.py -o .DEPS.git
 #   gclient runhooks
 # DO NOT CHECK IN CHANGES TO .DEPS.git. It will be automatically updated by
 # a bot when you modify this one.
@@ skipping 17 matching lines @@
   "chromiumos_git": "https://chromium.googlesource.com/chromiumos",
   "skia_git": "https://skia.googlesource.com",
   "swig_revision": "230490",
   "nacl_revision": "12773",
   # After changing nacl_revision, run 'glient sync' and check native_client/DEPS
   # to update other nacl_*_revision's.
   "nacl_tools_revision": "12760",  # native_client/DEPS: tools_rev
   "google_toolbox_for_mac_revision": "626",
   "libaddressinput_revision": "176",
   "libphonenumber_revision": "621",
-  "libvpx_revision": "248011",
+  "libvpx_revision": "251850",
   "lss_revision": "24",
 
   # These two FFmpeg variables must be updated together.  One is used for SVN
   # checkouts and the other for Git checkouts.
   "ffmpeg_revision": "249179",
   "ffmpeg_hash": "4ae5e54f30f949e5485d70fa0eae85a0e75cb46c",
 
   "sfntly_revision": "228",
   "lighttpd_revision": "33737",
   "skia_revision": "13441",
@@ skipping 704 matching lines @@
                 "-s", "src/build/linux/bin/eu-strip.sha1",
     ],
   },
   {
     # A change to a .gyp, .gypi, or to GYP itself should run the generator.
     "name": "gyp",
     "pattern": ".",
     "action": ["python", "src/build/gyp_chromium"],
   },
 ]