Reviewed by Anders.

    Reviewed by Anders.

        - add QueryInterface capabilities to COMPtr

        * platform/win/COMPtr.h:
        (COMPtr::COMPtr): Added constructor that takes a Query tag and
        does an appropriate QueryInterface.
        (COMPtr::query): Added function to do a queryInterface.
        (COMPtr::copyQueryInterfaceRef): Added private helper used by
        both of the above. Note that when the query fails you get a 0,
        which is the same thing you get if a 0 pointer is passed in.

        * platform/win/FontCacheWin.cpp:
        (WebCore::FontCache::getFontLinkInterface): Convert to using
        the new query as a test case. Also eliminate the unnecessary
        second global variable and use COMPtr objects rather than just
        leaking references.

        * platform/win/WCDataObject.h: Removed unneeded include and
        using statements.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@25690 268f45cc-cd09-0410-ab3c-d52691b4dbfc