Re-implement app overlap detection with new extent syntax.

BUG=47445

Review URL: http://codereview.chromium.org/2876009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@50929 0039d316-1c4b-4281-b951-d872f2087c98
7 files changed