Move InvalidationGuard/InstanceUpdateBlocker out of SVGElementInstance

Source/core/svg/SVGElement.h

Index: Source/core/svg/SVGElement.h
diff --git a/Source/core/svg/SVGElement.h b/Source/core/svg/SVGElement.h
index 741a43ec220f48897878eb8374b549cddfe4fe1d..e91f7e3eb7840125cfd9342f6a154bf4944afae6 100644
--- a/Source/core/svg/SVGElement.h
+++ b/Source/core/svg/SVGElement.h
@@ -155,6 +155,27 @@ public:
 
     bool inUseShadowTree() const;
 
+    class InstanceInvalidationGuard {

[pdr., 2014/05/05 21:00:15]

I would have left this as InvalidationGuard since the instance concept will be
going away soon.

+        WTF_MAKE_NONCOPYABLE(InstanceInvalidationGuard);
+    public:
+        InstanceInvalidationGuard(SVGElement* element) : m_element(element) { }
+        ~InstanceInvalidationGuard() { SVGElement::invalidateAllInstancesOfElement(m_element); }
+    private:
+        SVGElement* m_element;
+    };
+
+    class InstanceUpdateBlocker {
+        WTF_MAKE_NONCOPYABLE(InstanceUpdateBlocker);
+    public:
+        InstanceUpdateBlocker(SVGElement* targetElement);
+        ~InstanceUpdateBlocker();
+
+    private:
+        SVGElement* m_targetElement;
+    };
+
+    static void invalidateAllInstancesOfElement(SVGElement*);
+
 protected:
     SVGElement(const QualifiedName&, Document&, ConstructionType = CreateSVGElement);