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 e7cc3c9764d4a14e751ec64036114680d44ae057..70cb02bab3a97d8b85f864076e6aafe3e7efde83 100644
--- a/Source/core/svg/SVGUseElement.cpp
+++ b/Source/core/svg/SVGUseElement.cpp
@@ -444,33 +444,46 @@ void SVGUseElement::toClipPath(Path& path)
 {
     ASSERT(path.isEmpty());
 
+    const SVGGraphicsElement* element = targetGraphicsElementForClipping();
+
+    if (!element)
+        return;
+
+    if (!isDirectReference(*element)) {
+        // Spec: Indirect references are an error (14.3.5)
+        document().accessSVGExtensions().reportError("Not allowed to use indirect reference in <clip-path>");
+    } else 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;
-    SVGElement& element = toSVGElement(*n);
+        return nullptr;
 
+    SVGElement& element = toSVGElement(*n);
     if (element.isSVGGraphicsElement()) {
-        if (!isDirectReference(element)) {
-            // Spec: Indirect references are an error (14.3.5)
-            document().accessSVGExtensions().reportError("Not allowed to use indirect reference in <clip-path>");
-        } 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());
-        }
+        if (isSVGTextElement(element) || isSVGTSpanElement(element) || element.isSVGGeometryElement())

[pdr., 2015/06/17 04:42:13]

Lets add a link to the spec here.
// 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

Can you also move the isDirectReference check and reportError call here instead
of in toClipPath?

+            return &toSVGGraphicsElement(element);
     }
+
+    return nullptr;
 }
 
 LayoutObject* SVGUseElement::layoutObjectClipChild() const

[pdr., 2015/06/17 04:42:13]

This function is pretty simple now, can you move this logic into
LayoutSVGResourceClipper::createContentPicture and remove
SVGUseElement::layoutObjectClipChild?

 {
-    if (Node* n = userAgentShadowRoot()->firstChild()) {
-        if (n->isSVGElement() && isDirectReference(toSVGElement(*n)))
-            return n->layoutObject();
-    }
+    const SVGGraphicsElement* element = targetGraphicsElementForClipping();
 
-    return nullptr;
+    if (!element)
+        return nullptr;
+
+    return element->layoutObject();
 }
 
 bool SVGUseElement::buildShadowTree(SVGElement* target, SVGElement* targetInstance, bool foundUse)