Slimming Paint phase 2 compositing algorithm plumbing & skeleton display list API.

Source/core/layout/compositing/CompositedDeprecatedPaintLayerMapping.cpp

 /*
  * Copyright (C) 2009, 2010, 2011 Apple Inc. 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.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 2064 matching lines @@
 
     // Convert from ancestor to local coordinates.
     IntSize ancestorToLocalOffset = paintInfo.offsetFromLayoutObject - ancestorPaintInfo->offsetFromLayoutObject;
     parentClipRect.move(ancestorToLocalOffset);
     return parentClipRect;
 }
 
 void CompositedDeprecatedPaintLayerMapping::doPaintTask(const GraphicsLayerPaintInfo& paintInfo, const PaintLayerFlags& paintLayerFlags, GraphicsContext* context,
     const IntRect& clip) // In the coords of rootLayer.
 {
+    ASSERT(!RuntimeEnabledFeatures::slimmingPaintCompositorLayerizationEnabled() || clip == LayoutRect::infiniteIntRect());
+
     FontCachePurgePreventer fontCachePurgePreventer;
 
     IntSize offset = paintInfo.offsetFromLayoutObject;
     AffineTransform translation;
     translation.translate(-offset.width(), -offset.height());
     TransformRecorder transformRecorder(*context, *this, translation);
 
     // The dirtyRect is in the coords of the painting root.
     IntRect dirtyRect(clip);
     dirtyRect.move(offset);
@@ skipping 261 matching lines @@
     } else if (graphicsLayer == m_scrollingBlockSelectionLayer.get()) {
         name = "Scrolling Block Selection Layer";
     } else {
         ASSERT_NOT_REACHED();
     }
 
     return name;
 }
 
 } // namespace blink