Remove CSS regions support, keeping a bare minimum to support "region-based" multicol.

Source/core/rendering/RenderLayer.h

 /*
  * Copyright (C) 2003, 2009, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Intel Corporation. All rights reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
@@ skipping 259 matching lines @@
 
     void convertToPixelSnappedLayerCoords(const RenderLayer* ancestorLayer, IntPoint& location) const;
     void convertToPixelSnappedLayerCoords(const RenderLayer* ancestorLayer, IntRect&) const;
     void convertToLayerCoords(const RenderLayer* ancestorLayer, LayoutPoint& location) const;
     void convertToLayerCoords(const RenderLayer* ancestorLayer, LayoutRect&) const;
 
     // The two main functions that use the layer system.  The paint method
     // paints the layers that intersect the damage rect from back to
     // front.  The hitTest method looks for mouse events by walking
     // layers that intersect the point from front to back.
-    void paint(GraphicsContext*, const LayoutRect& damageRect, PaintBehavior = PaintBehaviorNormal, RenderObject* paintingRoot = 0,
-        RenderRegion* = 0, PaintLayerFlags = 0);
+    void paint(GraphicsContext*, const LayoutRect& damageRect, PaintBehavior = PaintBehaviorNormal, RenderObject* paintingRoot = 0, PaintLayerFlags = 0);
     bool hitTest(const HitTestRequest&, HitTestResult&);
     bool hitTest(const HitTestRequest&, const HitTestLocation&, HitTestResult&);
     void paintOverlayScrollbars(GraphicsContext*, const LayoutRect& damageRect, PaintBehavior, RenderObject* paintingRoot = 0);
 
     // Pass offsetFromRoot if known.
     bool intersectsDamageRect(const LayoutRect& layerBounds, const LayoutRect& damageRect, const RenderLayer* rootLayer, const LayoutPoint* offsetFromRoot = 0) const;
 
     enum CalculateLayerBoundsFlag {
         IncludeSelfTransform = 1 << 0,
         UseLocalClipRectIfPossible = 1 << 1,
@@ skipping 225 matching lines @@
 
     LayoutPoint renderBoxLocation() const { return renderer()->isBox() ? toRenderBox(renderer())->location() : LayoutPoint(); }
 
     void paintLayerContentsAndReflection(GraphicsContext*, const LayerPaintingInfo&, PaintLayerFlags);
     void paintLayerByApplyingTransform(GraphicsContext*, const LayerPaintingInfo&, PaintLayerFlags, const LayoutPoint& translationOffset = LayoutPoint());
     void paintLayerContents(GraphicsContext*, const LayerPaintingInfo&, PaintLayerFlags);
     void paintChildren(unsigned childrenToVisit, GraphicsContext*, const LayerPaintingInfo&, PaintLayerFlags);
     void paintPaginatedChildLayer(RenderLayer* childLayer, GraphicsContext*, const LayerPaintingInfo&, PaintLayerFlags);
     void paintChildLayerIntoColumns(RenderLayer* childLayer, GraphicsContext*, const LayerPaintingInfo&, PaintLayerFlags, const Vector<RenderLayer*>& columnLayers, size_t columnIndex);
 
-    void collectFragments(LayerFragments&, const RenderLayer* rootLayer, RenderRegion*, const LayoutRect& dirtyRect,
+    void collectFragments(LayerFragments&, const RenderLayer* rootLayer, const LayoutRect& dirtyRect,
         ClipRectsType, OverlayScrollbarSizeRelevancy inOverlayScrollbarSizeRelevancy = IgnoreOverlayScrollbarSize,
         ShouldRespectOverflowClip = RespectOverflowClip, const LayoutPoint* offsetFromRoot = 0,
         const LayoutSize& subPixelAccumulation = LayoutSize(), const LayoutRect* layerBoundingBox = 0);
     void updatePaintingInfoForFragments(LayerFragments&, const LayerPaintingInfo&, PaintLayerFlags, bool shouldPaintContent, const LayoutPoint* offsetFromRoot);
     void paintBackgroundForFragments(const LayerFragments&, GraphicsContext*, GraphicsContext* transparencyLayerContext,
         const LayoutRect& transparencyPaintDirtyRect, bool haveTransparency, const LayerPaintingInfo&, PaintBehavior, RenderObject* paintingRootForRenderer);
     void paintForegroundForFragments(const LayerFragments&, GraphicsContext*, GraphicsContext* transparencyLayerContext,
         const LayoutRect& transparencyPaintDirtyRect, bool haveTransparency, const LayerPaintingInfo&, PaintBehavior, RenderObject* paintingRootForRenderer,
         bool selectionOnly, bool forceBlackText);
     void paintForegroundForFragmentsWithPhase(PaintPhase, const LayerFragments&, GraphicsContext*, const LayerPaintingInfo&, PaintBehavior, RenderObject* paintingRootForRenderer);
@@ skipping 224 matching lines @@
 
 } // namespace WebCore
 
 #ifndef NDEBUG
 // Outside the WebCore namespace for ease of invocation from gdb.
 void showLayerTree(const WebCore::RenderLayer*);
 void showLayerTree(const WebCore::RenderObject*);
 #endif
 
 #endif // RenderLayer_h