Improve TypeError messages from failed array conversions.

Source/bindings/v8/custom/V8MessageEventCustom.cpp

 /*
  * Copyright (C) 2009 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 100 matching lines @@
     if (args[6]->IsObject()) {
         v8::Handle<v8::Object> wrapper = v8::Handle<v8::Object>::Cast(args[6]);
         v8::Handle<v8::Object> window = wrapper->FindInstanceInPrototypeChain(V8Window::GetTemplate(args.GetIsolate(), worldTypeInMainThread(args.GetIsolate())));
         if (!window.IsEmpty())
             sourceArg = V8Window::toNative(window);
     }
     OwnPtr<MessagePortArray> portArray;
 
     if (!isUndefinedOrNull(args[7])) {
         portArray = adoptPtr(new MessagePortArray);
-        if (!getMessagePortArray(args[7], *portArray, args.GetIsolate()))
+        if (!getMessagePortArray(args[7], 8, *portArray, args.GetIsolate()))

[Mike West, 2013/10/24 07:08:54]

This isn't really your fault, since this call is already full of magic numbers,
but I'd appreciate it if you changed "7" and "8" in this line to something
readable. 'const int portArrayIndex = 7' and 'portArrayIndex + 1' or something
similar.

[sof, 2013/10/24 21:16:41]

good idea, done.

I filed http://code.google.com/p/chromium/issues/detail?id=311332 on
deprecating&removing this method.

             return;
     }
     event->initMessageEvent(typeArg, canBubbleArg, cancelableArg, originArg, lastEventIdArg, sourceArg, portArray.release());
 
     if (!dataArg.IsEmpty()) {
         args.Holder()->SetHiddenValue(V8HiddenPropertyName::data(args.GetIsolate()), dataArg);
         if (isolatedWorldForIsolate(args.GetIsolate()))
             event->setSerializedData(SerializedScriptValue::createAndSwallowExceptions(dataArg, args.GetIsolate()));
     }
 }
 
 void V8MessageEvent::webkitInitMessageEventMethodCustom(const v8::FunctionCallbackInfo<v8::Value>& args)
 {
     initMessageEventMethodCustom(args);
 }
 
 
 } // namespace WebCore