Remove SVGElementInstance

Source/core/svg/SVGElement.cpp

Index: Source/core/svg/SVGElement.cpp
diff --git a/Source/core/svg/SVGElement.cpp b/Source/core/svg/SVGElement.cpp
index 7f1904c2b9d4b2db6f74236dd3ac24ed2f8dae74..f22e0885c55b9cff899f07cb13c9ceb9000f55b8 100644
--- a/Source/core/svg/SVGElement.cpp
+++ b/Source/core/svg/SVGElement.cpp
@@ -107,6 +107,20 @@ SVGElement::~SVGElement()
 #endif
 }
 
+void SVGElement::detach(const AttachContext& context)
+{
+    Element::detach(context);
+    if (correspondingElement() && correspondingElement()->instancesForElement().contains(this))

[pdr., 2014/06/04 04:07:52]

Can we make instancesForElement protected and move the contains logic into
removeInstanceMapping?

+        correspondingElement()->removeInstanceMapping(this);
+}
+
+void SVGElement::attach(const AttachContext& context)
+{
+    Element::attach(context);
+    if (correspondingElement())
+        correspondingElement()->mapInstanceToElement(this);
+}
+
 short SVGElement::tabIndex() const
 {
     if (supportsFocus())
@@ -1042,6 +1056,8 @@ void SVGElement::invalidateInstances()
         }
     }
 
+    svgRareData()->elementInstances().clear();
+
     document().updateRenderTreeIfNeeded();
 }