Remove completely unreferenced flag.

BUG=350124
R=thakis@chromium.org

Review URL: https://codereview.chromium.org/189383002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@255668 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 255668