> Scrollbar and scroll corner composited layers positioned incorrectly
> Patch by James Robinson <email@example.com>
; on 2013-01-29
> Reviewed by Simon Fraser.
> ScrollView::updateScrollbars() needs to update the overflow controls composited layers if scrollbars are added
> or removed. It was doing this by recording on entry to the function if it had horizontal or vertical scrollbars
> and then comparing that to m_horizontal/verticalScrollbar on exit. Unfortunately updateScrollbars is recursive
> and exits without running the postamble code when nested on the callstack. As a result, scrollbars may be
> added or removed several times during the recursion, possibly leaving the overflow control layers in an
> inconsistent state, while ending up with the same set of scrollbars.
> This changes the "has anything changed" logic to only compare local state (hasXXXScrollbar vs
> newHasXXXScrollbar) so changes in recursive calls are not considered.
> * platform/ScrollView.cpp: