Set MessageEvent.source to the newly created port for shared workers' connect events

Source/core/dom/MessageEvent.idl

Index: Source/core/dom/MessageEvent.idl
diff --git a/Source/core/dom/MessageEvent.idl b/Source/core/dom/MessageEvent.idl
index 3bc8866a7ea1161a7c75dadb015e8e6873ad2cd7..33d1c33f462579cc125443c9a8fd11f0db37596f 100644
--- a/Source/core/dom/MessageEvent.idl
+++ b/Source/core/dom/MessageEvent.idl
@@ -31,7 +31,7 @@
 ] interface MessageEvent : Event {
     [InitializedByEventConstructor] readonly attribute DOMString origin;
     [InitializedByEventConstructor] readonly attribute DOMString lastEventId;
-    [InitializedByEventConstructor] readonly attribute Window source;
+    [InitializedByEventConstructor] readonly attribute EventTarget source; // May be a Window or a MessagePort

[abarth-chromium, 2013/08/19 19:24:58]

Is that enforced by the constructor?

I would remove this comment.

[do-not-use, 2013/08/19 19:45:57]

The specification is using (Window or MessagePort) type, which our bindings
generator does not support. Instead, I decided to use a common parent type
(EventTarget) and add a comment. I do think that the comment helps understanding
what source is.

     [InitializedByEventConstructor, CustomGetter] readonly attribute any data;
     [InitializedByEventConstructor] readonly attribute MessagePort[] ports;