- fix http://bugzilla.opendarwin.org/show_bug.cgi?id=8023
          Attribute.h missing class predeclaration

        * dom/Attribute.h: Add declarations for classes so that the friend
        declaration is not the only one. There's an issue with either an earlier
        or later version of gcc, which is why we see this only on certain platforms.

        * dom/Attr.cpp:
        (WebCore::Attr::Attr):
        (WebCore::Attr::~Attr):
        * dom/NamedAttrMap.cpp:
        (WebCore::NamedAttrMap::clearAttributes):
        (WebCore::NamedAttrMap::addAttribute):
        (WebCore::NamedAttrMap::removeAttribute):
        Change places where practical to use attr() instead of m_impl in the vain
        hope of removing the need for the friend declarations.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@13533 268f45cc-cd09-0410-ab3c-d52691b4dbfc