Revert of Roll webrtc 6905:6948.

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 37 matching lines @@
   "lighttpd_revision": "33737",
   "skia_revision": "4082d290eea2f70caa82120ff3bc4fbdccbf206c",
   # 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": "23233",
   # 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": "6948",
+  "webrtc_revision": "6905",
   "jsoncpp_revision": "248",
   "nss_revision": "289430",
   # 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": "b8aeeaef087fa2571aaaf64a8a8dbec06a0e0e41",
   # 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": "284247",
@@ skipping 757 matching lines @@
     # migration completes (let's say Sep 1 2014).
     "name": "check_git_config",
     "pattern": ".",
     "action": [
         "python",
         "src/tools/check_git_config.py",
         "--running-as-hook",
     ],
   },
 ]