Revert of Roll webrtc 5122:5218

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 32 matching lines @@
   "lighttpd_revision": "33737",
   "skia_revision": "12472",
   "skia_hash": "11e055518a0cbe5329232a55fe2cd177e83836d8",
   # 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": "18251",
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling WebRTC
   # and V8 without interference from each other.
-  "webrtc_revision": "5218",
+  "webrtc_revision": "5122",
   "jsoncpp_revision": "248",
   "nss_revision": "235242",
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling swarming_client
   # and whatever else without interference from each other.
   "swarming_revision": "aab3a62beb7e1d7a6785dcaee707479691fd6ddf",
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling openssl
   # and whatever else without interference from each other.
   "openssl_revision": "236537",
@@ skipping 629 matching lines @@
     "pattern": ".",
     "action": ["python", "src/build/gyp_chromium"],
   },
   {
     # Check for landmines (reasons to clobber the build).
     "name": "landmines",
     "pattern": ".",
     "action": ["python", "src/build/landmines.py"],
   },
 ]