Reviewed by Maciej Stachowiak.

        Remove custom bindings for PopStateEvent.initPopStateEvent
        https://bugs.webkit.org/show_bug.cgi?id=38311

        Our code generation of SerializedScriptValue was slightly buggy, but
        it's easy to fix.  Notice that the conversion to an atomic string is
        handled by the C++ type system and doesn't require logic in the code
        generator.

        * bindings/js/JSPopStateEventCustom.cpp:
        * bindings/scripts/CodeGeneratorJS.pm:
        * bindings/scripts/CodeGeneratorV8.pm:
        * bindings/scripts/test/GObject/WebKitDOMTestObj.cpp:
        (webkit_dom_test_obj_serialized_value):
        * bindings/scripts/test/GObject/WebKitDOMTestObj.h:
        * bindings/scripts/test/JS/JSTestObj.cpp:
        (WebCore::):
        (WebCore::jsTestObjPrototypeFunctionSerializedValue):
        * bindings/scripts/test/JS/JSTestObj.h:
        * bindings/scripts/test/ObjC/DOMTestObj.h:
        * bindings/scripts/test/ObjC/DOMTestObj.mm:
        (-[DOMTestObj serializedValue:]):
        * bindings/scripts/test/TestObj.idl:
        * bindings/scripts/test/V8/V8TestObj.cpp:
        (WebCore::TestObjInternal::serializedValueCallback):
        (WebCore::ConfigureV8TestObjTemplate):
        * bindings/v8/custom/V8PopStateEventCustom.cpp:
        * dom/PopStateEvent.idl:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@58504 268f45cc-cd09-0410-ab3c-d52691b4dbfc