Expose v8 context a MessagePort lives in to give content side code a valid context to (de)serialize…

Source/core/dom/MessagePort.cpp

 /*
  * 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 248 matching lines @@
     }
     return portArray.release();
 }
 
 void MessagePort::trace(Visitor* visitor)
 {
     ActiveDOMObject::trace(visitor);
     EventTargetWithInlineData::trace(visitor);
 }
 
+v8::Isolate* MessagePort::scriptIsolate()
+{
+    ASSERT(executionContext());
+    return toIsolate(executionContext());
+}
+
+v8::Handle<v8::Context> MessagePort::scriptContext()
+{
+    ASSERT(executionContext());
+    return toV8Context(executionContext(), DOMWrapperWorld::mainWorld());
+}
+
 } // namespace blink