Update renderer's resize corner rect cached in RenderWidgetHost only on resize ack.
Update renderer's resize corner rect cached in RenderWidgetHost only on resize ack.

BUG=64113
TEST=browser_tests should pass.

Review URL: http://codereview.chromium.org/5368001

git-svn-id: http://src.chromium.org/svn/trunk/src@67292 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: b69da5139b4d98d256a6fa4af0a39a6e47543d53
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