Fixed: <rdar://problem/3555137> REGRESSION (125-173): Flash animation can erase...

	Fixed: <rdar://problem/3555137> REGRESSION (125-173): Flash animation can erase parts of chrome (bookmarks bar & tab bar)

	convertRect:toView: returns incorrect results inside of viewWillMoveToWindow: with a nil window. Workaround this by catching this case.

        Reviewed by darin.

        * Plugins.subproj/WebBaseNetscapePluginView.m:
        (-[WebBaseNetscapePluginView superviewsHaveSuperviews]): new
        (-[WebBaseNetscapePluginView saveAndSetPortStateForUpdate:]): clip out the plug-in view when superviewsHaveSuperviews returns NO

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@8520 268f45cc-cd09-0410-ab3c-d52691b4dbfc