Revert of Revert of Divorce PaintInvalidationState from LayoutState

Source/core/rendering/RenderFlowThread.cpp

 /*
  * Copyright (C) 2011 Adobe Systems Incorporated. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1. Redistributions of source code must retain the above
  *    copyright notice, this list of conditions and the following
  *    disclaimer.
@@ skipping 147 matching lines @@
         return false;
 
     return true;
 }
 
 void RenderFlowThread::repaintRectangleInRegions(const LayoutRect& repaintRect) const
 {
     if (!shouldRepaint(repaintRect) || !hasValidRegionInfo())
         return;
 
-    ForceHorriblySlowRectMapping slowRectMapping(*this); // We can't use layout state to repaint, since the regions are somewhere else.
-
     // We can't use currentFlowThread as it is possible to have interleaved flow threads and the wrong one could be used.
     // Let each columnSet figure out the proper enclosing flow thread.
     CurrentRenderFlowThreadDisabler disabler(view());
 
     for (RenderMultiColumnSetList::const_iterator iter = m_multiColumnSetList.begin(); iter != m_multiColumnSetList.end(); ++iter) {
         RenderMultiColumnSet* columnSet = *iter;
 
         columnSet->repaintFlowThreadContent(repaintRect);
     }
 }
@@ skipping 332 matching lines @@
 {
     if (!m_renderFlowThread)
         return;
     RenderView* view = m_renderFlowThread->view();
     ASSERT(view->flowThreadController()->currentRenderFlowThread() == m_renderFlowThread);
     view->flowThreadController()->setCurrentRenderFlowThread(m_previousRenderFlowThread);
 }
 
 
 } // namespace WebCore