Merge 141226

Merge 141226
> Scrollbar and scroll corner composited layers positioned incorrectly
> https://bugs.webkit.org/show_bug.cgi?id=108255
> 
> Patch by James Robinson <jamesr@chromium.org>; 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:
> (WebCore::ScrollView::updateScrollbars):

TBR=jamesr@chromium.org
BUG=170264
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=141507

[teo, 2013-03-06 09:56:56]

On 2013/02/01 01:02:55, jamesr wrote:

I am having the same issue.  Here is a page that has the exact same issue.  For
what it's worth, if you hide anything below the description-box-clear element,
it shows fine.  http://www.johnspassvillage.net/JPMA/26-food-and-drink I am
willing to help out if you need it in changing the code on the website side -
might help your troubleshooting on a third-party website???