Roll libvpx 278497:278986

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 -w <gclientdir>
 # where <gcliendir> is the absolute path to the directory containing the
 # .gclient file (the parent of "src").
 #
@@ skipping 23 matching lines @@
   "pdfium_git": "https://pdfium.googlesource.com",
   "skia_git": "https://skia.googlesource.com",
   "swig_revision": "230490",
   "nacl_revision": "13377",
   # After changing nacl_revision, run 'glient sync' and check native_client/DEPS
   # to update other nacl_*_revision's.
   "nacl_tools_revision": "13077",  # native_client/DEPS: tools_rev
   "google_toolbox_for_mac_revision": "662",
   "libaddressinput_revision": "293",
   "libphonenumber_revision": "621",
-  "libvpx_revision": "278497",
+  "libvpx_revision": "278986",
   "lss_revision": "26",
   "sfntly_revision": "239",
   "lighttpd_revision": "33737",
   "skia_revision": "4a995dfff2ecf91e8bf999d77e3218cec596232c",
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling Skia
   # and V8 without interference from each other.
   "v8_branch": "trunk",
   "v8_revision": "21910",
   # Three lines of non-changing comments so that
@@ skipping 786 matching lines @@
                 "src/third_party/apache-win32",
     ],
   },
   {
     # A change to a .gyp, .gypi, or to GYP itself should run the generator.
     "name": "gyp",
     "pattern": ".",
     "action": ["python", "src/build/gyp_chromium"],
   },
 ]