Allow external whitelisted protocols on the Mac.
Allow external whitelisted protocols on the Mac.

http://crbug.com/12287

Review URL: http://codereview.chromium.org/115660

git-svn-id: http://src.chromium.org/svn/trunk/src@16657 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 108be6c5124f748382a46fa57109d6e96410d856
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