Make mac build with deprecation warnings on

By sending "window" to a forward declared class, clang can't
verify that the call is correct.

BUG=324299
R=thakis@chromium.org

Review URL: https://codereview.chromium.org/95013003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@237816 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 237816