cros: Kiosk apps settings UI.

- Add a kiosk section in browser options when app mode is
  enabled and current user is owner (or running on dev box);
- Click on the manage button brings up a kiosk app settings
  overlay;
- The overlay allows user to add, remove and set app to be
  auto launched. And a simple error handling by showing
  bad app in an error banner for 5 seconds;

BUG=173749
TEST=Verify kiosk apps could be added, removed and set as
     auto launch. Only one could be auto launched. Invalid
     app should show up in an error banner.

R=zelidrag@chromium.org,dbeam@chromium.org
TBR=sky@chromium.org for gyp changes

Review URL: https://chromiumcodereview.appspot.com/12213033

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@182985 0039d316-1c4b-4281-b951-d872f2087c98
16 files changed