Reviewed by Geoff.
        
        Fix for <rdar://problem/5499125>
        REGRESSION (r21367): After launching Kidzui beta, a webview frame fails to appear in its main window
        
        If window object properties were modified when it had initial empty document (synchronously after 
        window.open() for example) those modifications were lost when the real document was switched in.
        
        Match Firefox behavior where window properties are not cleared if the inital document and the loaded one
        have matching security domains.

        Tests: fast/dom/Window/window-early-properties.html
               http/tests/security/window-properties-clear-domain.html
               http/tests/security/window-properties-clear-port.html
               http/tests/security/window-properties-pass.html

        * WebCore.exp:
        * loader/FrameLoader.cpp:
        (WebCore::FrameLoader::FrameLoader):
        (WebCore::FrameLoader::init):
        (WebCore::FrameLoader::clear):
        (WebCore::FrameLoader::isSecureTransition):
        (WebCore::FrameLoader::begin):
        * loader/FrameLoader.h:
        If we are transitioning from initial empty document to the final one, do a domain security check
        between old security policy URL and new URL. If that passes don't clear script proxy and script objects.
        
        * bindings/js/kjs_proxy.cpp:
        (WebCore::KJSProxy::updateDocumentWrapper):
        * bindings/js/kjs_proxy.h:
        * page/Frame.cpp:
        (WebCore::Frame::setDocument):
        Since we don't always clear window properties anymore, we need to update the document property to point to
        the newly created one. 

LayoutTests:

        Reviewed by Geoff.
        
        Tests for <rdar://problem/5499125>
        REGRESSION (r21359-21368): After launching Kidzui beta, a webview frame fails to appear in its main window

        * fast/dom/Window/window-early-properties-expected.txt: Added.
        * fast/dom/Window/window-early-properties.html: Added.
        * http/tests/security/resources/has-custom-property.html: Added.
        * http/tests/security/resources/no-custom-property.html: Added.
        * http/tests/security/window-properties-clear-domain-expected.txt: Added.
        * http/tests/security/window-properties-clear-domain.html: Added.
        * http/tests/security/window-properties-clear-port-expected.txt: Added.
        * http/tests/security/window-properties-clear-port.html: Added.
        * http/tests/security/window-properties-pass-expected.txt: Added.
        * http/tests/security/window-properties-pass.html: Added.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@25783 268f45cc-cd09-0410-ab3c-d52691b4dbfc