Move toClipPath to SVGGeometryElement.

Source/core/svg/SVGUseElement.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007 Rob Buis <buis@kde.org>
  * Copyright (C) Research In Motion Limited 2009-2010. All rights reserved.
  * Copyright (C) 2011 Torch Mobile (Beijing) Co. Ltd. All rights reserved.
  * Copyright (C) 2012 University of Szeged
  * Copyright (C) 2012 Renata Hodovan <reni@webkit.org>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 422 matching lines @@
 {
     return isSVGPathElement(element)
         || isSVGRectElement(element)
         || isSVGCircleElement(element)
         || isSVGEllipseElement(element)
         || isSVGPolygonElement(element)
         || isSVGPolylineElement(element)
         || isSVGTextElement(element);
 }
 
 void SVGUseElement::toClipPath(Path& path)

[fs, 2015/06/22 10:57:44]

const qualify the method?

 {
     ASSERT(path.isEmpty());
 
+    const SVGGraphicsElement* element = targetGraphicsElementForClipping();
+
+    if (!element)
+        return;
+
+    if (element->isSVGGeometryElement()) {
+        toSVGGeometryElement(*element).toClipPath(path);
+        // FIXME: Avoid manual resolution of x/y here. Its potentially harmful.
+        SVGLengthContext lengthContext(this);
+        path.translate(FloatSize(m_x->currentValue()->value(lengthContext), m_y->currentValue()->value(lengthContext)));
+        path.transform(calculateAnimatedLocalTransform());
+    }
+}
+
+SVGGraphicsElement* SVGUseElement::targetGraphicsElementForClipping() const
+{
     Node* n = userAgentShadowRoot()->firstChild();
     if (!n || !n->isSVGElement())
-        return;
+        return nullptr;
+
     SVGElement& element = toSVGElement(*n);
 
     if (element.isSVGGraphicsElement()) {

[fs, 2015/06/22 10:57:44]

Suggest you turn this into the negation to flatten the control-flow a bit:

if (!element.isSVGGraphicsElement())
    return nullptr;

+        // Spec: "If a <use> element is a child of a clipPath element, it must directly
+        // reference <path>, <text> or basic shapes elements. Indirect references are an
+        // error and the clipPath element must be ignored."
+        // http://dev.w3.org/fxtf/css-masking-1/#the-clip-path
         if (!isDirectReference(element)) {
+            if (isSVGClipPathElement(element))

[fs, 2015/06/22 10:57:44]

There's nothing special with <clipPath> in this case, so remove this.

+                return nullptr;
             // Spec: Indirect references are an error (14.3.5)
             document().accessSVGExtensions().reportError("Not allowed to use indirect reference in <clip-path>");

[fs, 2015/06/22 10:57:44]

Add return after this (or the method will still return the element.) 

-        } else {
-            toSVGGraphicsElement(element).toClipPath(path);
-            // FIXME: Avoid manual resolution of x/y here. Its potentially harmful.
-            SVGLengthContext lengthContext(this);
-            path.translate(FloatSize(m_x->currentValue()->value(lengthContext), m_y->currentValue()->value(lengthContext)));
-            path.transform(calculateAnimatedLocalTransform());
         }
-    }
-}
 
-LayoutObject* SVGUseElement::layoutObjectClipChild() const
-{
-    if (Node* n = userAgentShadowRoot()->firstChild()) {
-        if (n->isSVGElement() && isDirectReference(toSVGElement(*n)))
-            return n->layoutObject();
+        return &toSVGGraphicsElement(element);
     }
 
     return nullptr;
 }
 
 bool SVGUseElement::buildShadowTree(SVGElement* target, SVGElement* targetInstance, bool foundUse)
 {
     ASSERT(target);
     ASSERT(targetInstance);
 
@@ skipping 293 matching lines @@
 
     if (m_resource)
         m_resource->removeClient(this);
 
     m_resource = resource;
     if (m_resource)
         m_resource->addClient(this);
 }
 
 }