Re-enable tab switching test.
Re-enable tab switching test.

Disabled in r33278 but works locally for me.  Need to
re-enable to test if it is still failing on the slaves.

BUG=28968
TEST=tab switching test runs on slaves

Review URL: http://codereview.chromium.org/466060

git-svn-id: http://src.chromium.org/svn/trunk/src@33997 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 7d8e59efb355009a76d5d6687545df491f760bf4
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