Reviewed by Eric Seidel.

        Introduce the notion of a "display-isolated" URL scheme for use by
        Chrome-internal URLs
        https://bugs.webkit.org/show_bug.cgi?id=50182

        This patch actually makes the display-isolated schemes display
        isolated.  The behavior should be the same as the previous iteration of
        this patch, but re-organized a bit because reading the access white
        list is expensive.

        * page/SecurityOrigin.cpp:
        (WebCore::SecurityOrigin::isAccessToURLWhiteListed):
        (WebCore::SecurityOrigin::canDisplay):
        * page/SecurityOrigin.h:
        * platform/SchemeRegistry.cpp:
        * platform/SchemeRegistry.h:


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@75557 268f45cc-cd09-0410-ab3c-d52691b4dbfc