O2D Mac: Don't crash if the user tries to go to fullscreen with O2D.
O2D Mac: Don't crash if the user tries to go to fullscreen with O2D.

TEST=tried to go fullscreen with O2D on Mac in FF, Chrome, and Sarafi and verified nothing happens
BUG=none

Review URL: http://codereview.chromium.org/6650012

git-svn-id: http://src.chromium.org/svn/trunk/src@77389 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: dd6694613f7c81a705f455ab517c78aa5cc84a84
meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser