https://bugs.webkit.org/show_bug.cgi?id=117835

Patch by Radu Stavila <stavila@adobe.com> on 2013-06-21
Reviewed by Andreas Kling.

Moved computeOversetStateForRegions() and overset() methods from RenderFlowThread to RenderNamedFlowThread.
Added ASSERTS in RenderRegion::regionOversetState and RenderRegion::setRegionOversetState to ensure
the region was created from an element.

* rendering/RenderBlock.cpp:
(WebCore::RenderBlock::computeOverflow):
* rendering/RenderFlowThread.cpp:
(WebCore::RenderFlowThread::RenderFlowThread):
* rendering/RenderFlowThread.h:
* rendering/RenderNamedFlowThread.cpp:
(WebCore::RenderNamedFlowThread::RenderNamedFlowThread):
(WebCore::RenderNamedFlowThread::computeOversetStateForRegions):
* rendering/RenderNamedFlowThread.h:
(WebCore::RenderNamedFlowThread::overset):
* rendering/RenderRegion.cpp:
(WebCore::RenderRegion::regionOversetState):
(WebCore::RenderRegion::setRegionOversetState):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@151843 268f45cc-cd09-0410-ab3c-d52691b4dbfc