Reviewed by john
        
        <rdar://problem/4920742>
        REGRESSION: GMail Editor: Attempting to remove formatting from selection results in a crash at WebCore::Range::checkDeleteEx

WebCore:

        Reviewed by john

        <rdar://problem/4920742>
        REGRESSION: GMail Editor: Attempting to remove formatting from selection results in a crash at WebCore::Range::checkDeleteExtract()

        * dom/Range.cpp:
        (WebCore::Range::checkDeleteExtract): Return if there is no
        commonAncestor container or if commonAncestorContainer() throws
        an exception.
        * editing/Editor.cpp:
        (WebCore::Editor::removeFormattingAndStyle): Fixed a bug that reversed
        the order of the selected paragraphs.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@19055 268f45cc-cd09-0410-ab3c-d52691b4dbfc