Run Mutation Observer and Custom Element callbacks consistently at microtask checkpoint

Source/core/dom/Microtask.cpp

 /*
- * Copyright (C) 2012 Google Inc. All rights reserved.
+ * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer
  *    in the documentation and/or other materials provided with the
  *    distribution.
  * 3. Neither the name of Google Inc. nor the names of its contributors
  *    may be used to endorse or promote products derived from this
  *    software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifndef RTCSessionDescriptionCallback_h
-#define RTCSessionDescriptionCallback_h
+#include "config.h"
+#include "core/dom/Microtask.h"
 
-#include "wtf/RefCounted.h"
+#include "core/dom/CustomElementCallbackDispatcher.h"
+#include "core/dom/MutationObserver.h"
+#include "wtf/Vector.h"
 
 namespace WebCore {
 
-class RTCSessionDescription;
+void Microtask::performCheckpoint()
+{
+    static bool performingCheckpoint = false;
+    if (performingCheckpoint)
+        return;
+    performingCheckpoint = true;
 
-class RTCSessionDescriptionCallback : public RefCounted<RTCSessionDescriptionCallback> {
-public:
-    virtual ~RTCSessionDescriptionCallback() { }
-    virtual bool handleEvent(RTCSessionDescription*) = 0;
-};
+    bool anyWorkDone;
+    do {
+        MutationObserver::deliverAllMutations();
+        anyWorkDone = CustomElementCallbackDispatcher::instance().dispatch();
+    } while (anyWorkDone);
+
+    performingCheckpoint = false;
+}
 
 } // namespace WebCore
-
-#endif // RTCSessionDescriptionCallback_h