Make the VoidCallback DOM interface behave more like our other DOM interfaces.
        
        * bindings/js/JSCustomVoidCallback.h: Added.
        * bindings/js/JSCustomVoidCallback.cpp: Added.
        (WebCore::JSCustomVoidCallback::JSCustomVoidCallback):
        (WebCore::JSCustomVoidCallback::handleEvent):
        VoidCallback implementation that wraps a JS object.
        
        (WebCore::toVoidCallback):
        New method that creates a VoidCallback implementation given a JS object.
        
        * bindings/scripts/CodeGeneratorJS.pm:
        Specify that VoidCallback can fail conversion and add a custom conversion function.
        
        * html/HTMLMediaElement.cpp:
        (WebCore::HTMLMediaElement::movieCuePointReached):
        Call handleEvent on the callback.
        
        (WebCore::HTMLMediaElement::removeCuePoint):
        Comment out parts of this method, it has already been removed in the HTML5 spec and it relies
        on overriding VoidCallback equality.
        
        * html/VoidCallback.cpp: Removed.
        
        * html/VoidCallback.h:
        (WebCore::VoidCallback::VoidCallback):
        (WebCore::VoidCallback::~VoidCallback):
        Make this an abstract class with a pure virtual handleEvent method.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@27826 268f45cc-cd09-0410-ab3c-d52691b4dbfc