Move toClipPath to SVGGeometryElement.

Source/core/svg/SVGUseElement.cpp

Index: Source/core/svg/SVGUseElement.cpp
diff --git a/Source/core/svg/SVGUseElement.cpp b/Source/core/svg/SVGUseElement.cpp
index e56f7c78d65ffa83f4748ca4b87916614e959905..ccd58d2b4e23fe0c4655482917cbad093eb0c5df 100644
--- a/Source/core/svg/SVGUseElement.cpp
+++ b/Source/core/svg/SVGUseElement.cpp
@@ -444,30 +444,41 @@ void SVGUseElement::toClipPath(Path& path)
 {
     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;