Modifications to DisplayList for better Slimming Paint

Source/core/rendering/svg/RenderSVGResourceClipper.cpp

 /*
  * Copyright (C) 2004, 2005, 2007, 2008 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Rob Buis <buis@kde.org>
  * Copyright (C) Research In Motion Limited 2009-2010. All rights reserved.
  * Copyright (C) 2011 Dirk Schulze <krit@webkit.org>
  *
  * 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.
@@ skipping 227 matching lines @@
 
     AffineTransform contentTransformation;
     SVGUnitTypes::SVGUnitType contentUnits = toSVGClipPathElement(element())->clipPathUnits()->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_clipContentDisplayList)
-        m_clipContentDisplayList = asDisplayList(context, contentTransformation);
+        createDisplayList(context, contentTransformation);
 
     ASSERT(m_clipContentDisplayList);
     context->drawDisplayList(m_clipContentDisplayList.get());
 }
 
-PassRefPtr<DisplayList> RenderSVGResourceClipper::asDisplayList(GraphicsContext* context,
+void RenderSVGResourceClipper::createDisplayList(GraphicsContext* context,
     const AffineTransform& contentTransformation)
 {
     ASSERT(context);
     ASSERT(frame());
 
     // 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_clipContentDisplayList = DisplayList::create(bounds);
+    context->beginRecording(m_clipContentDisplayList);
 
     // Switch to a paint behavior where all children of this <clipPath> will be rendered using special constraints:
     // - fill-opacity/stroke-opacity/opacity set to 1
     // - masker/filter not applied when rendering the children
     // - fill is set to the initial fill paint server (solid, black)
     // - stroke is set to the initial stroke paint server (none)
     PaintBehavior oldBehavior = frame()->view()->paintBehavior();
     frame()->view()->setPaintBehavior(oldBehavior | PaintBehaviorRenderingSVGMask);
 
     for (SVGElement* childElement = Traversal<SVGElement>::firstChild(*element()); childElement; childElement = Traversal<SVGElement>::nextSibling(*childElement)) {
@@ skipping 23 matching lines @@
         context->setFillRule(newClipRule);
 
         if (isUseElement)
             renderer = childElement->renderer();
 
         SVGRenderingContext::renderSubtree(context, renderer, contentTransformation);
     }
 
     frame()->view()->setPaintBehavior(oldBehavior);
 
-    return context->endRecording();
+    context->endRecording();
 }
 
 void RenderSVGResourceClipper::calculateClipContentPaintInvalidationRect()
 {
     // This is a rough heuristic to appraise the clip size and doesn't consider clip on clip.
     for (SVGElement* childElement = Traversal<SVGElement>::firstChild(*element()); childElement; childElement = Traversal<SVGElement>::nextSibling(*childElement)) {
         RenderObject* renderer = childElement->renderer();
         if (!renderer)
             continue;
         if (!renderer->isSVGShape() && !renderer->isSVGText() && !isSVGUseElement(*childElement))
@@ skipping 55 matching lines @@
         AffineTransform transform;
         transform.translate(objectBoundingBox.x(), objectBoundingBox.y());
         transform.scaleNonUniform(objectBoundingBox.width(), objectBoundingBox.height());
         return transform.mapRect(m_clipBoundaries);
     }
 
     return m_clipBoundaries;
 }
 
 }