Reviewed by Tim Hatcher.

    Reviewed by Tim Hatcher.

        - eliminated the need for UsesPassRefPtr in IDL files
        - got rid of the category mechanism for ObjC generated DOM headers
          (after discussions with Tim H where we decided it's not needed)
        - simplified use of macro inside ObjC generated code

        * ForwardingHeaders/wtf/GetPtr.h: Added.

        * bindings/scripts/CodeGeneratorObjC.pm: Removed code to handle
        categories. Eliminated use of DOM_cast since that's for the protection
        of human programmers -- the script won't make mistakes that it needs
        to catch. Changed macro to always be named IMPL instead of incorporating
        the class name. Use WTF::getPtr to extract the pointer, and removed the
        code that uses .get() to extract the pointer in the PassRefPtr case.

        * dom/Attr.idl: Removed all uses of UsesPassRefPtr and ObjCCatagory.
        * dom/DOMImplementation.idl: Ditto.
        * dom/Document.idl: Ditto.
        * dom/Element.idl: Ditto.
        * dom/NamedNodeMap.idl: Ditto.
        * html/HTMLDocument.idl: Ditto.
        * html/HTMLElement.idl: Ditto.
        * html/HTMLFormElement.idl: Ditto.
        * html/HTMLMapElement.idl: Ditto.
        * html/HTMLSelectElement.idl: Ditto.
        * html/HTMLTableElement.idl: Ditto.
        * html/HTMLTableRowElement.idl: Ditto.
        * html/HTMLTableSectionElement.idl: Ditto.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@16134 268f45cc-cd09-0410-ab3c-d52691b4dbfc