Fixing build break when WebRTC is disabled.

TBR=dmichael@chromium.org,joi@chromium.org
BUG=318673

Review URL: https://codereview.chromium.org/70473004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@234802 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 234802