Fixes bug where instant preview would not show in certain situations. This would happen if the RenderWidgetHost changed before the first paint.
Fixes bug where instant preview would not show in certain
situations. This would happen if the RenderWidgetHost changed before
the first paint.

BUG=none
TEST=none

Review URL: http://codereview.chromium.org/5373003

git-svn-id: http://src.chromium.org/svn/trunk/src@67581 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 1fe873177c17452c394c7336aff3dac935f30fe1
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