Use an SVGElementProxy in ReferenceClipPathOperation

third_party/WebKit/Source/core/paint/ClipPathClipper.cpp

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/paint/ClipPathClipper.h"
 
 #include "core/layout/svg/LayoutSVGResourceClipper.h"
 #include "core/layout/svg/SVGResources.h"
 #include "core/layout/svg/SVGResourcesCache.h"
 #include "core/paint/SVGClipPainter.h"
 #include "core/style/ClipPathOperation.h"
 #include "platform/graphics/paint/ClipPathRecorder.h"
 
 namespace blink {
 
 namespace {
 
 LayoutSVGResourceClipper* resolveElementReference(
     const LayoutObject& layoutObject,
     const ReferenceClipPathOperation& referenceClipPathOperation) {
   if (layoutObject.isSVG() && !layoutObject.isSVGRoot()) {
     // The reference will have been resolved in
     // SVGResources::buildResources, so we can just use the LayoutObject's
     // SVGResources.
     SVGResources* resources =
         SVGResourcesCache::cachedResourcesForLayoutObject(&layoutObject);
     return resources ? resources->clipper() : nullptr;
   }
-  // TODO(fs): It doesn't work with forward or external SVG references
-  // (https://bugs.webkit.org/show_bug.cgi?id=90405)
-  Element* element = layoutObject.document().getElementById(
-      referenceClipPathOperation.fragment());
+  // TODO(fs): Doesn't work with external SVG references (crbug.com/109212.)
+  Node* targetNode = layoutObject.node();
+  if (!targetNode)
+    return nullptr;
+  SVGElement* element =
+      referenceClipPathOperation.findElement(targetNode->treeScope());
   if (!isSVGClipPathElement(element) || !element->layoutObject())
     return nullptr;
   return toLayoutSVGResourceClipper(
       toLayoutSVGResourceContainer(element->layoutObject()));
 }
 
 }  // namespace
 
 ClipPathClipper::ClipPathClipper(GraphicsContext& context,
                                  ClipPathOperation& clipPathOperation,
@@ skipping 35 matching lines @@
   }
 }
 
 ClipPathClipper::~ClipPathClipper() {
   if (m_resourceClipper)
     SVGClipPainter(*m_resourceClipper)
         .finishEffect(m_layoutObject, m_context, m_clipperState);
 }
 
 }  // namespace blink