Implement Custom Elements' attributeChangedCallback.

Source/core/dom/CustomElementCallbackInvocation.h

Index: Source/core/dom/CustomElementCallbackInvocation.h
diff --git a/Source/core/dom/Microtask.h b/Source/core/dom/CustomElementCallbackInvocation.h
similarity index 67%
copy from Source/core/dom/Microtask.h
copy to Source/core/dom/CustomElementCallbackInvocation.h
index 27f72cbec01e5795593d3e545a3b5ca3e5c046fa..0e46c6354aa684344334219cabd95157e2f27a1e 100644
--- a/Source/core/dom/Microtask.h
+++ b/Source/core/dom/CustomElementCallbackInvocation.h
@@ -28,19 +28,29 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifndef Microtask_h
-#define Microtask_h
+#ifndef CustomElementCallbackInvocation_h
+#define CustomElementCallbackInvocation_h
+
+#include "wtf/PassOwnPtr.h"
+#include "wtf/text/AtomicString.h"
 
 namespace WebCore {
 
-class Microtask {
+class CustomElementLifecycleCallbacks;
+class Element;
+
+class CustomElementCallbackInvocation {
+    WTF_MAKE_NONCOPYABLE(CustomElementCallbackInvocation);
 public:
-    static void performCheckpoint();
+    static PassOwnPtr<CustomElementCallbackInvocation> createCreatedInvocation();
+    static PassOwnPtr<CustomElementCallbackInvocation> createAttributeChangedInvocation(const AtomicString& name, const AtomicString& oldValue, const AtomicString& newValue);
+
+    CustomElementCallbackInvocation() { }
+    virtual ~CustomElementCallbackInvocation() { }
 
-private:
-    explicit Microtask();
+    virtual void dispatch(CustomElementLifecycleCallbacks*, Element*) = 0;
 };
 
 }
 
-#endif // Microtask_h
+#endif // CustomElementCallbackInvocation_h