Ensure display items are unique when multiple nested clip paths are used

third_party/WebKit/Source/core/layout/svg/LayoutSVGResourceClipper.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 140 matching lines @@
         transform.translate(referenceBox.x(), referenceBox.y());
         transform.scaleNonUniform(referenceBox.width(), referenceBox.height());
         clipPath.transform(transform);
     }
 
     // Transform path by animatedLocalTransform.
     clipPath.transform(animatedLocalTransform);
     return true;
 }
 
-PassRefPtr<const SkPicture> LayoutSVGResourceClipper::createContentPicture(AffineTransform& contentTransformation, const FloatRect& targetBoundingBox,

[chrishtr, 2016/03/29 17:59:04]

SVGMaskPainter also calls this method, does that code need to be updated?

[pdr., 2016/03/29 18:06:15]

We should be good there, as SVGMaskPainter only calls
LayoutSVGResourceMasker::createContentPicture.

-    GraphicsContext& context)
+PassRefPtr<const SkPicture> LayoutSVGResourceClipper::createContentPicture()
 {
     ASSERT(frame());
-
-    if (clipPathUnits() == SVGUnitTypes::SVG_UNIT_TYPE_OBJECTBOUNDINGBOX) {
-        contentTransformation.translate(targetBoundingBox.x(), targetBoundingBox.y());
-        contentTransformation.scaleNonUniform(targetBoundingBox.width(), targetBoundingBox.height());
-    }
-
     if (m_clipContentPicture)
         return m_clipContentPicture;
 
-    SubtreeContentTransformScope contentTransformScope(contentTransformation);
-
     // 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).
     FloatRect bounds = strokeBoundingBox();
 
-    SkPictureBuilder pictureBuilder(bounds, nullptr, &context);
+    SkPictureBuilder pictureBuilder(bounds, nullptr, nullptr);
 
     for (SVGElement* childElement = Traversal<SVGElement>::firstChild(*element()); childElement; childElement = Traversal<SVGElement>::nextSibling(*childElement)) {
         LayoutObject* layoutObject = childElement->layoutObject();
         if (!layoutObject)
             continue;
 
         const ComputedStyle* style = layoutObject->style();
         if (!style || style->display() == NONE || style->visibility() != VISIBLE)
             continue;
 
@@ skipping 93 matching lines @@
         AffineTransform transform;
         transform.translate(objectBoundingBox.x(), objectBoundingBox.y());
         transform.scaleNonUniform(objectBoundingBox.width(), objectBoundingBox.height());
         return transform.mapRect(m_clipBoundaries);
     }
 
     return m_clipBoundaries;
 }
 
 } // namespace blink