[CSSRegions] Move regions auto-size code into RenderNamedFlowFragment
https://bugs.webkit.org/show_bug.cgi?id=122959

Reviewed by Mihnea Ovidenie.

Move the auto-height logic from RenderRegion to RenderNamedFlowFragment because it's
used only by the CSS Regions implementation.

Bug 126642 covers the auto-height logic move from RenderFlowThread to RenderNamedFlowThread.

Tests: No new tests, just refactorings.

* rendering/RenderFlowThread.cpp:
(WebCore::RenderFlowThread::styleDidChange):
(WebCore::RenderFlowThread::validateRegions):
(WebCore::RenderFlowThread::isAutoLogicalHeightRegionsCountConsistent):
(WebCore::RenderFlowThread::initializeRegionsComputedAutoHeight):
(WebCore::RenderFlowThread::markAutoLogicalHeightRegionsForLayout):
(WebCore::RenderFlowThread::updateRegionsFlowThreadPortionRect):
(WebCore::RenderFlowThread::addForcedRegionBreak):
* rendering/RenderMultiColumnSet.h:
* rendering/RenderNamedFlowFragment.cpp:
(WebCore::RenderNamedFlowFragment::RenderNamedFlowFragment):
(WebCore::RenderNamedFlowFragment::styleDidChange):
(WebCore::RenderNamedFlowFragment::incrementAutoLogicalHeightCount):
(WebCore::RenderNamedFlowFragment::decrementAutoLogicalHeightCount):
(WebCore::RenderNamedFlowFragment::updateRegionHasAutoLogicalHeightFlag):
(WebCore::RenderNamedFlowFragment::updateLogicalHeight):
(WebCore::RenderNamedFlowFragment::pageLogicalHeight):
(WebCore::RenderNamedFlowFragment::layoutBlock):
(WebCore::RenderNamedFlowFragment::attachRegion):
(WebCore::RenderNamedFlowFragment::detachRegion):
* rendering/RenderNamedFlowFragment.h:
* rendering/RenderRegion.cpp:
(WebCore::RenderRegion::RenderRegion):
(WebCore::RenderRegion::pageLogicalHeight):
(WebCore::RenderRegion::logicalHeightOfAllFlowThreadContent):
(WebCore::RenderRegion::isLastRegion):
(WebCore::RenderRegion::styleDidChange):
(WebCore::RenderRegion::attachRegion):
(WebCore::RenderRegion::detachRegion):
* rendering/RenderRegion.h:
* rendering/RenderRegionSet.h:
* rendering/RenderTreeAsText.cpp:
(WebCore::writeRenderRegionList):


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@161553 268f45cc-cd09-0410-ab3c-d52691b4dbfc