sync-webkit-git: a better message when you're not on the right branch
sync-webkit-git: a better message when you're not on the right branch

Review URL: http://codereview.chromium.org/235056

git-svn-id: http://src.chromium.org/svn/trunk/src@27560 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 2e38f33490ad7309613b9bcd432222fe178ca287
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