Simplify invokeCallback() and support void return values for IDL callbacks

Source/bindings/tests/results/V8TestCallback.h

 /*
  * Copyright (C) 2013 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 26 matching lines @@
 #include "bindings/v8/ActiveDOMCallback.h"
 #include "bindings/v8/DOMWrapperWorld.h"
 #include "bindings/v8/ScopedPersistent.h"
 
 namespace WebCore {
 
 class ExecutionContext;
 
 class V8TestCallback : public TestCallback, public ActiveDOMCallback {
 public:
-    static PassOwnPtr<V8TestCallback> create(v8::Handle<v8::Object> callback, ExecutionContext* context)
+    static PassOwnPtr<V8TestCallback> create(v8::Handle<v8::Function> callback, ExecutionContext* context)
     {
         ASSERT(context);
         return adoptPtr(new V8TestCallback(callback, context));
     }
 
     virtual ~V8TestCallback();
 
     virtual bool callbackWithNoArg();
     virtual bool callbackWithTestInterfaceEmptyArg(TestInterfaceEmpty* class1Arg);
     virtual bool callbackWithTestInterfaceEmptyArg(TestInterfaceEmpty* class2Arg, const String& strArg);
     virtual bool customCallback(TestInterfaceEmpty* testInterfaceEmptyArg, TestInterfaceEmpty* testInterfaceEmptyArg);
     virtual bool callbackWithBooleanArg(bool boolArg);
     virtual bool callbackWithSequenceArg(const Vector<RefPtr<TestInterfaceEmpty> >& sequenceArg);
     virtual bool callbackWithFloatArg(float floatArg);
     virtual bool callbackWithThisArg(ScriptValue thisValue, int arg);
+    virtual void callbackWithVoidReturnValue();
 private:
-    V8TestCallback(v8::Handle<v8::Object>, ExecutionContext*);
+    V8TestCallback(v8::Handle<v8::Function>, ExecutionContext*);
 
-    ScopedPersistent<v8::Object> m_callback;
+    ScopedPersistent<v8::Function> m_callback;
     RefPtr<DOMWrapperWorld> m_world;
 };
 
 }
 #endif // V8TestCallback_h