sync (cros): Don't try to migrate tokens on cros.
sync (cros): Don't try to migrate tokens on cros.

BUG=chromium-os:7396
TEST=None :(

Review URL: http://codereview.chromium.org/3710004

git-svn-id: http://src.chromium.org/svn/trunk/src@62427 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: b038918aa991349038233af708e6406bb9364765
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