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

Source/core/inspector/InspectorFileSystemAgent.cpp

 /*
  * Copyright (C) 2011, 2012 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 71 matching lines @@
 template<typename BaseCallback, typename Handler, typename Argument>
 class CallbackDispatcher : public BaseCallback {
 public:
     typedef bool (Handler::*HandlingMethod)(Argument);
 
     static PassOwnPtr<CallbackDispatcher> create(PassRefPtr<Handler> handler, HandlingMethod handlingMethod)
     {
         return adoptPtr(new CallbackDispatcher(handler, handlingMethod));
     }
 
-    virtual bool handleEvent(Argument argument) OVERRIDE
+    virtual void handleEvent(Argument argument) OVERRIDE
     {
-        return (m_handler.get()->*m_handlingMethod)(argument);
+        (m_handler.get()->*m_handlingMethod)(argument);
     }
 
 private:
     CallbackDispatcher(PassRefPtr<Handler> handler, HandlingMethod handlingMethod)
         : m_handler(handler)
         , m_handlingMethod(handlingMethod) { }
 
     RefPtr<Handler> m_handler;
     HandlingMethod m_handlingMethod;
 };
@@ skipping 407 matching lines @@
 
 private:
     // CallbackDispatcherFactory doesn't handle 0-arg handleEvent methods
     class VoidCallbackImpl : public VoidCallback {
     public:
         explicit VoidCallbackImpl(PassRefPtr<DeleteEntryRequest> handler)
             : m_handler(handler)
         {
         }
 
-        virtual bool handleEvent() OVERRIDE
+        virtual void handleEvent() OVERRIDE
         {
-            return m_handler->didDeleteEntry();
+            m_handler->didDeleteEntry();
         }
 
     private:
         RefPtr<DeleteEntryRequest> m_handler;
     };
 
     bool didHitError(FileError* error)
     {
         reportResult(error->code());
         return true;
@@ skipping 185 matching lines @@
     for (Frame* frame = m_pageAgent->mainFrame(); frame; frame = frame->tree().traverseNext()) {
         if (frame->document() && frame->document()->securityOrigin()->isSameSchemeHostPort(origin))
             return frame->document();
     }
 
     *error = "No frame is available for the request";
     return 0;
 }
 
 } // namespace WebCore