Fix compile error on lkgr Win x64 build.

R=calamity@chromium.org

Review URL: https://codereview.chromium.org/24856003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@225669 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 225669