Re-instate geometry sharing optimization for 'd' on <use>'d <path>s

third_party/WebKit/Source/core/svg/SVGPathElement.cpp

Index: third_party/WebKit/Source/core/svg/SVGPathElement.cpp
diff --git a/third_party/WebKit/Source/core/svg/SVGPathElement.cpp b/third_party/WebKit/Source/core/svg/SVGPathElement.cpp
index fb1f808cb01ee5362a7ac594d89bdee6e909736d..c0a5e54abb40b744d9e5d45ad2bbe5a52211d9e1 100644
--- a/third_party/WebKit/Source/core/svg/SVGPathElement.cpp
+++ b/third_party/WebKit/Source/core/svg/SVGPathElement.cpp
@@ -152,10 +152,15 @@ void SVGPathElement::svgAttributeChanged(const QualifiedName& attrName)
 void SVGPathElement::collectStyleForPresentationAttribute(const QualifiedName& name, const AtomicString& value, MutableStylePropertySet* style)
 {
     SVGAnimatedPropertyBase* property = propertyFromAttribute(name);
-    if (property == m_path)
-        addPropertyToPresentationAttributeStyle(style, CSSPropertyD, m_path->currentValue()->pathValue());
-    else
-        SVGGeometryElement::collectStyleForPresentationAttribute(name, value, style);
+    if (property == m_path) {
+        SVGAnimatedPath* path = this->path();
+        // If this is a <use> instance, return the referenced path to maximize geometry sharing.
+        if (const SVGElement* element = correspondingElement())
+            path = toSVGPathElement(element)->path();
+        addPropertyToPresentationAttributeStyle(style, CSSPropertyD, path->currentValue()->pathValue());
+        return;
+    }
+    SVGGeometryElement::collectStyleForPresentationAttribute(name, value, style);
 }
 
 void SVGPathElement::invalidateMPathDependencies()