Initial implementation of stashed message ports, blink side

Source/core/dom/MessagePort.h

 /*
  * Copyright (C) 2008 Apple 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
@@ skipping 37 matching lines @@
 class MessagePort;
 class ScriptState;
 class SerializedScriptValue;
 
 // The overwhelmingly common case is sending a single port, so handle that efficiently with an inline buffer of size 1.
 typedef WillBeHeapVector<RefPtrWillBeMember<MessagePort>, 1> MessagePortArray;
 
 // Not to be confused with WebMessagePortChannelArray; this one uses Vector and OwnPtr instead of WebVector and raw pointers.
 typedef Vector<OwnPtr<WebMessagePortChannel>, 1> MessagePortChannelArray;
 
-class CORE_EXPORT MessagePort final
+class CORE_EXPORT MessagePort
     : public EventTargetWithInlineData
     , public RefCountedWillBeNoBase<MessagePort>
     , public ActiveDOMObject
     , public WebMessagePortChannelClient {
     DEFINE_WRAPPERTYPEINFO();
     REFCOUNTED_EVENT_TARGET(MessagePort);
     WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(MessagePort);
 public:
     static PassRefPtrWillBeRawPtr<MessagePort> create(ExecutionContext&);
     virtual ~MessagePort();
@@ skipping 33 matching lines @@
     EventListener* onmessage() { return getAttributeEventListener(EventTypeNames::message); }
 
     // A port starts out its life entangled, and remains entangled until it is closed or is cloned.
     bool isEntangled() const { return !m_closed && !isNeutered(); }
 
     // A port gets neutered when it is transferred to a new owner via postMessage().
     bool isNeutered() const { return !m_entangledChannel; }
 
     DECLARE_VIRTUAL_TRACE();
 
+protected:
+    explicit MessagePort(ExecutionContext&);
+    bool tryGetMessage(RefPtr<SerializedScriptValue>& message, OwnPtr<MessagePortChannelArray>& channels);
+
 private:
-    explicit MessagePort(ExecutionContext&);
-
     // WebMessagePortChannelClient implementation.
     virtual void messageAvailable() override;
     virtual v8::Isolate* scriptIsolate() override;
     virtual v8::Local<v8::Context> scriptContextForMessageConversion() override;
     void dispatchMessages();
 
     OwnPtr<WebMessagePortChannel> m_entangledChannel;
 
     bool m_started;
     bool m_closed;
 
     WeakPtrFactory<MessagePort> m_weakFactory;
 
     RefPtr<ScriptState> m_scriptStateForConversion;
 };
 
 } // namespace blink
 
 #endif // MessagePort_h