Fix issue where transparent window background wouldn't show up until after you'd dragged a tab out, then back in, then out again. BUG=21580 TEST=tab dragging Review URL: http://codereview.chromium.org/373011
Fix issue where transparent window background wouldn't show up until after you'd dragged a tab out, then back in, then out again.
BUG=21580
TEST=tab dragging
Review URL: http://codereview.chromium.org/373011

git-svn-id: http://src.chromium.org/svn/trunk/src@31236 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 27a09ad317bddc1f8faf3377a087c03295d70599
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