appear when loading a page with a Horizontal scrollbar from 
the back/forward cache.

Reviewed by Sam Weinig.

This patch adds a new  bool member variable to FrameView to 
keep track of whether we are loading a page from the back/
forward cache. If we are, don't suppress scrollbars on 
first layout.
* history/CachedFrame.cpp:
(WebCore::CachedFrameBase::restore):
* page/FrameView.cpp:
(WebCore::FrameView::FrameView):
(WebCore::FrameView::reset):
(WebCore::FrameView::layout):
* page/FrameView.h:
(WebCore::FrameView::setIsRestoringFromBackForward):
(WebCore::FrameView::isRestoringFromBackForward):



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@79053 268f45cc-cd09-0410-ab3c-d52691b4dbfc