to be asynchronous. However, the actually delegate method is not
	async yet.

        * WebView.subproj/WebFramePrivate.h:
        * WebView.subproj/WebFramePrivate.m:
        (-[WebFrame _checkNavigationPolicyForRequest:dataSource:andCall:withSelector:]):
        (-[WebFrame _continueFragmentScrollAfterNavigationPolicy:request:]):
        (-[WebFrame _loadURL:loadType:triggeringEvent:isFormSubmission:]):
        (-[WebFrame _continueLoadRequestAfterNavigationPolicy:request:]):
        (-[WebFrame _loadDataSource:withLoadType:]):
        * WebView.subproj/WebMainResourceClient.h:
        * WebView.subproj/WebMainResourceClient.m:
        (-[WebMainResourceClient stopLoadingForPolicyChange]):
        (-[WebMainResourceClient continueAfterNavigationPolicy:request:]):
        (-[WebMainResourceClient handle:willSendRequest:]):
        (-[WebMainResourceClient handle:didReceiveResponse:]):


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@2686 268f45cc-cd09-0410-ab3c-d52691b4dbfc