Reviewed by Brady.

        When in the web archive debug mode, don't call didFail immediately. Instead,
        add the loader to the substitute resource map, but with a null resource, which
        indicates to substituteResourceDeliveryTimerFired that the load should fail.
        
        * loader/DocumentLoader.cpp:
        (WebCore::DocumentLoader::substituteResourceDeliveryTimerFired):
        (WebCore::DocumentLoader::scheduleArchiveLoad):
        * loader/ResourceLoader.cpp:
        (WebCore::ResourceLoader::load):



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@32017 268f45cc-cd09-0410-ab3c-d52691b4dbfc