[cros] Fix issue with focus stealing when choosing user picture with left/right arrows.

BUG=chromium-os:19007
TEST=manual


Review URL: http://codereview.chromium.org/7715033

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@98408 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/resources/chromeos/login/oobe_screen_user_image.js

@@ -132,6 +132,7 @@ cr.define('oobe', function() {
         if (prevIndex > 0)
           UserImageScreen.selectUserImage(prevIndex - 1);
       }
+      e.stopPropagation();
     });
   };