Run Mutation Observer and Custom Element callbacks consistently at microtask checkpoint

Source/core/dom/CustomElementCallbackDispatcher.h

Index: Source/core/dom/CustomElementCallbackDispatcher.h
diff --git a/Source/core/platform/mediastream/RTCConfiguration.h b/Source/core/dom/CustomElementCallbackDispatcher.h
similarity index 51%
copy from Source/core/platform/mediastream/RTCConfiguration.h
copy to Source/core/dom/CustomElementCallbackDispatcher.h
index ddb5adbdfae20b5efb6d41aa63596dd3304b8912..46a4f76b65ae122e3ad47fd8ee66d813103a57c5 100644
--- a/Source/core/platform/mediastream/RTCConfiguration.h
+++ b/Source/core/dom/CustomElementCallbackDispatcher.h
@@ -1,5 +1,5 @@
 /*
- * 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
@@ -28,57 +28,59 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifndef RTCConfiguration_h
-#define RTCConfiguration_h
+#ifndef CustomElementCallbackDispatcher_h
+#define CustomElementCallbackDispatcher_h
 
-#include "weborigin/KURL.h"
+#include "core/dom/CustomElementCallback.h"
+#include "core/dom/Element.h"
 #include "wtf/PassRefPtr.h"
-#include "wtf/RefCounted.h"
+#include "wtf/RefPtr.h"
 #include "wtf/Vector.h"
-#include "wtf/text/WTFString.h"
 
 namespace WebCore {
 
-class RTCIceServer : public RefCounted<RTCIceServer> {
+class CustomElementCallbackDispatcher {
+    WTF_MAKE_NONCOPYABLE(CustomElementCallbackDispatcher);
 public:
-    static PassRefPtr<RTCIceServer> create(const KURL& uri, const String& username, const String& credential)
-    {
-        return adoptRef(new RTCIceServer(uri, username, credential));
-    }
-    virtual ~RTCIceServer() { }
+    static CustomElementCallbackDispatcher& instance();
 
-    const KURL& uri() { return m_uri; }
-    const String& username() { return m_username; }
-    const String& credential() { return m_credential; }
+    class CallbackDeliveryScope {
+    public:
+        CallbackDeliveryScope() { }
+        ~CallbackDeliveryScope()
+        {
+            CustomElementCallbackDispatcher& dispatcher = CustomElementCallbackDispatcher::instance();
+            if (dispatcher.hasQueuedCallbacks())
+                dispatcher.dispatch();
+        }
+    };
 
-private:
-    RTCIceServer(const KURL& uri, const String& username, const String& credential)
-        : m_uri(uri)
-        , m_username(username)
-        , m_credential(credential)
-    {
-    }
+    void enqueueReadyCallback(CustomElementCallback*, Element*);
 
-    KURL m_uri;
-    String m_username;
-    String m_credential;
-};
+    // Returns true if more work may have to be performed at the
+    // checkpoint by this or other workers (for example, this work
+    // invoked author scripts)
+    bool dispatch();
 
-class RTCConfiguration : public RefCounted<RTCConfiguration> {
-public:
-    static PassRefPtr<RTCConfiguration> create() { return adoptRef(new RTCConfiguration()); }
-    virtual ~RTCConfiguration() { }
+private:
+    explicit CustomElementCallbackDispatcher() { }
+
+    bool hasQueuedCallbacks() { return !m_invocations.isEmpty(); }
 
-    void appendServer(PassRefPtr<RTCIceServer> server) { m_servers.append(server); }
-    size_t numberOfServers() { return m_servers.size(); }
-    RTCIceServer* server(size_t index) { return m_servers[index].get(); }
+    class ReadyInvocation {
+    public:
+        ReadyInvocation(PassRefPtr<CustomElementCallback>, PassRefPtr<Element>);
+        virtual ~ReadyInvocation() { }
+        void invoke() { m_callback->ready(m_element.get()); }
 
- private:
-    RTCConfiguration() { }
+    private:
+        RefPtr<CustomElementCallback> m_callback;
+        RefPtr<Element> m_element;
+    };
 
-    Vector<RefPtr<RTCIceServer> > m_servers;
+    Vector<ReadyInvocation> m_invocations;
 };
 
-} // namespace WebCore
+}
 
-#endif // RTCConfiguration_h
+#endif // CustomElementCallbackDispatcher_h