Reviewed by Mitz.

        - a first small step of CSS DOM refactoring -- the eventual goal is to
          reduce StyleBase and possibly eliminate it, since it has multiple
          purposes and unneccessarily ties many classes together

        * css/CSSCursorImageValue.cpp:
        (WebCore::isSVGCursorIdentifier): Mark static so it has internal linkage.
        (WebCore::resourceReferencedByCursorElement): Ditto.
        (WebCore::CSSCursorImageValue::CSSCursorImageValue): Removed unused style
        argument.
        (WebCore::CSSCursorImageValue::updateIfSVGCursorIsUsed): Removed code to
        check if X and Y changed before changing them -- there's no reason to do
        that. Removed code that depended on the internals of CSSImageValue. The
        new code uses only protected functions rather than going right at the
        fields and uing internal knowledge of the base class.
        * css/CSSCursorImageValue.h: Added a create function, made constructor
        private, removed unused style argument.

        * css/CSSImageValue.cpp:
        (WebCore::CSSImageValue::CSSImageValue): Removed unused style argument.
        (WebCore::CSSImageValue::cachedImageURL): Added. A protected function for
        use by CSSCursorImageValue that gives the URL.
        (WebCore::CSSImageValue::clearCachedImage): Added. A protected function for
        use by CSSCursorImageValue that clears the CachedImage.
        * css/CSSImageValue.h: Added create functions, made constructors protected
        and private, removed unused style argument, made data members private, added
        some protected functions for use by CSSCursorImageValue.

        * css/CSSImportRule.cpp:
        (WebCore::CSSImportRule::setCSSStyleSheet): Changed to call checkLoaded on
        the parent. This is part of preparation to move the checkLoaded function from
        StyleBase to StyleSheet.
        (WebCore::CSSImportRule::insertedIntoParent): Changed code to check the URL
        of the style sheet to use the href function of the style sheet rather than
        the baseURL function. This eliminates an O(n^2) algorithm here and reduces
        the use of baseURL, part of preparation to move it from StyleBase
        to CSSStyleSheet.

        * css/CSSMutableStyleDeclaration.cpp:
        (WebCore::CSSMutableStyleDeclaration::setImageProperty): Changed to use create
        function instead of a direct call to new for the CSSImageValue classes.
        * css/CSSParser.cpp:
        (WebCore::CSSParser::parseValue): Ditto.
        (WebCore::CSSParser::parseContent): Ditto.
        (WebCore::CSSParser::parseFillImage): Ditto.
        (WebCore::CSSParser::parseBorderImage): Ditto.

        * css/CSSStyleSelector.cpp: Removed unneeded include of CSSImageValue.h.
        * rendering/style/RenderStyle.h: Removed unneeded include of
        CSSCursorImageValue.h, which was causing us to rebuild the world way too often.

        * xml/XSLImportRule.cpp:
        (WebCore::XSLImportRule::setXSLStyleSheet): See change to CSSImportRule above.
        (WebCore::XSLImportRule::loadSheet): Ditto.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@33934 268f45cc-cd09-0410-ab3c-d52691b4dbfc