GitLab

Special handling of CWS icon.
Also correctly handle URL rewrites in favicon requests.

BUG=chromium-os:28314,chromium:120471
TEST=Observe the right favicon for CWS and FileManager component extension. Bookmark them and see the right favicon.
Review URL: https://chromiumcodereview.appspot.com/9979001

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@133657 0039d316-1c4b-4281-b951-d872f2087c98