Mac: fix warnings for TabView.xib.
Mac: fix warnings for TabView.xib.

I told IB to reload class files and then saved. IB isn't so bright.

BUG=none
TEST=no warnings about "'HoverCloseButton' is not a kind of 'CloseButton'"

Review URL: http://codereview.chromium.org/500025

git-svn-id: http://src.chromium.org/svn/trunk/src@34567 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 8af900ffbcecca2301963cbafd464591e25ffda5
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