Reviewed by harrison

    Reviewed by harrison

        <rdar://problem/4808375>
        REGRESSION: TextIterator slowed down, affecting Find on Page & Copy (etc.) (11460)

        * editing/TextIterator.cpp:
        (WebCore::TextIterator::exitNode): Only create VisiblePositions
        when we're going to use them to create a range for an emitted character.
        We should further speed TextIterators up by avoiding creating VisiblePositions
        for TIs that are only used for the characters they emit (like the one that
        plainText uses).

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@17449 268f45cc-cd09-0410-ab3c-d52691b4dbfc