Bug 23741: StyleRareNonInheritedData::operator==() should not compare ContentData objects by pointer

        <https://bugs.webkit.org/show_bug.cgi?id=23741>

        Reviewed by Darin Adler.

        * rendering/style/RenderStyle.cpp:
        (WebCore::RenderStyle::contentDataEquivalent): Moved method to
        WebCore::StyleRareNonInheritedData class.
        * rendering/style/RenderStyle.h:
        (WebCore::InheritedFlags::contentDataEquivalent): Replaced declaration
        with inline method that calls contentDataEquivalent() on
        WebCore::StyleRareNonInheritedData instead.
        * rendering/style/StyleRareNonInheritedData.cpp:
        (WebCore::StyleRareNonInheritedData::operator==): This is the bug fix!
        Replaced pointer comparison of ContentData objects with call to
        StyleRareNonInheritedData::contentDataEquivalent().
        (WebCore::StyleRareNonInheritedData::contentDataEquivalent): Added.
        * rendering/style/StyleRareNonInheritedData.h:
        (WebCore::StyleRareNonInheritedData::contentDataEquivalent): Added
        declaration.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@40734 268f45cc-cd09-0410-ab3c-d52691b4dbfc