Reviewed by Hyatt, thumbs up by Darin.

        - test for http://bugs.webkit.org/show_bug.cgi?id=12782
          Reproducible crash in BidiContext::deref

        * fast/dynamic/anonymous-block-orphaned-lines-expected.checksum: Added.
        * fast/dynamic/anonymous-block-orphaned-lines-expected.png: Added.
        * fast/dynamic/anonymous-block-orphaned-lines-expected.txt: Added.
        * fast/dynamic/anonymous-block-orphaned-lines.html: Added.

WebCore:

        Reviewed by Hyatt, thumbs up by Darin.

        - fix http://bugs.webkit.org/show_bug.cgi?id=12782
          Reproducible crash in BidiContext::deref

        Test: fast/dynamic/anonymous-block-orphaned-lines.html

        * rendering/InlineBox.cpp:
        (WebCore::InlineBox::root): Added an assertion that we return a root inline box.
        * rendering/RenderBlock.cpp:
        (WebCore::RenderBlock::removeChild): Added code to adopt the line boxes of
        anonymous blocks being destroyed instead of leaving them orphaned, which
        is what caused this crash. The boxes will be deleted on the next layout, but
        this ensures consistency in the mean time.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@20188 268f45cc-cd09-0410-ab3c-d52691b4dbfc