Modifications to DisplayList for better Slimming Paint

Source/core/rendering/svg/RenderSVGResourceMasker.cpp

 /*
  * Copyright (C) Research In Motion Limited 2009-2010. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 104 matching lines @@
 
     AffineTransform contentTransformation;
     SVGUnitTypes::SVGUnitType contentUnits = toSVGMaskElement(element())->maskContentUnits()->currentValue()->enumValue();
     if (contentUnits == SVGUnitTypes::SVG_UNIT_TYPE_OBJECTBOUNDINGBOX) {
         contentTransformation.translate(targetBoundingBox.x(), targetBoundingBox.y());
         contentTransformation.scaleNonUniform(targetBoundingBox.width(), targetBoundingBox.height());
         context->concatCTM(contentTransformation);
     }
 
     if (!m_maskContentDisplayList)
-        m_maskContentDisplayList = asDisplayList(context, contentTransformation);
+        createDisplayList(context, contentTransformation);
     ASSERT(m_maskContentDisplayList);
     context->drawDisplayList(m_maskContentDisplayList.get());
 }
 
-PassRefPtr<DisplayList> RenderSVGResourceMasker::asDisplayList(GraphicsContext* context,
+void RenderSVGResourceMasker::createDisplayList(GraphicsContext* context,
     const AffineTransform& contentTransform)
 {
     ASSERT(context);
 
     // Using strokeBoundingBox (instead of paintInvalidationRectInLocalCoordinates) to avoid the intersection
     // with local clips/mask, which may yield incorrect results when mixing objectBoundingBox and
     // userSpaceOnUse units (http://crbug.com/294900).
-    context->beginRecording(strokeBoundingBox());
+    FloatRect bounds = strokeBoundingBox();
+    m_maskContentDisplayList = DisplayList::create(bounds);
+    context->beginRecording(m_maskContentDisplayList);
     for (SVGElement* childElement = Traversal<SVGElement>::firstChild(*element()); childElement; childElement = Traversal<SVGElement>::nextSibling(*childElement)) {
         RenderObject* renderer = childElement->renderer();
         if (!renderer)
             continue;
         RenderStyle* style = renderer->style();
         if (!style || style->display() == NONE || style->visibility() != VISIBLE)
             continue;
 
         SVGRenderingContext::renderSubtree(context, renderer, contentTransform);
     }
-
-    return context->endRecording();
+    context->endRecording();
 }
 
 void RenderSVGResourceMasker::calculateMaskContentPaintInvalidationRect()
 {
     for (SVGElement* childElement = Traversal<SVGElement>::firstChild(*element()); childElement; childElement = Traversal<SVGElement>::nextSibling(*childElement)) {
         RenderObject* renderer = childElement->renderer();
         if (!renderer)
             continue;
         RenderStyle* style = renderer->style();
         if (!style || style->display() == NONE || style->visibility() != VISIBLE)
@@ skipping 23 matching lines @@
         transform.translate(objectBoundingBox.x(), objectBoundingBox.y());
         transform.scaleNonUniform(objectBoundingBox.width(), objectBoundingBox.height());
         maskRect = transform.mapRect(maskRect);
     }
 
     maskRect.intersect(maskBoundaries);
     return maskRect;
 }
 
 }