Add messageerror event handler

third_party/WebKit/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 96 matching lines @@
   void ContextDestroyed(ExecutionContext*) override { close(); }
 
   void setOnmessage(EventListener* listener) {
     SetAttributeEventListener(EventTypeNames::message, listener);
     start();
   }
   EventListener* onmessage() {
     return GetAttributeEventListener(EventTypeNames::message);
   }
 
+  void setOnmessageerror(EventListener* listener) {
+    SetAttributeEventListener(EventTypeNames::messageerror, listener);
+    start();
+  }
+  EventListener* onmessageerror() {
+    return GetAttributeEventListener(EventTypeNames::messageerror);
+  }
+
   // A port starts out its life entangled, and remains entangled until it is
   // closed or is cloned.
   bool IsEntangled() const { return !closed_ && !IsNeutered(); }
 
   // A port gets neutered when it is transferred to a new owner via
   // postMessage().
   bool IsNeutered() const { return !entangled_channel_; }
 
   // For testing only: allows inspection of the entangled channel.
   WebMessagePortChannel* EntangledChannelForTesting() const {
@@ skipping 17 matching lines @@
   int pending_dispatch_task_ = 0;
   bool started_ = false;
   bool closed_ = false;
 
   RefPtr<WebTaskRunner> task_runner_;
 };
 
 }  // namespace blink
 
 #endif  // MessagePort_h