Reviewed by Darin Adler.

        - another fix for <rdar://problem/6617298> Typing delete on an unquoted
          blank line unquotes the preceding, quoted blank line

        Test: editing/deleting/type-delete-after-quote-2.html

        * editing/DeleteSelectionCommand.cpp:
        (WebCore::DeleteSelectionCommand::DeleteSelectionCommand): Initialize
        m_startsAtEmptyLine.
        (WebCore::DeleteSelectionCommand::handleSpecialCaseBRDelete): When the
        selection starts at an empty line, do not prevent the merging of blocks.
        This is what allows the text after the line break to be merged into the
        block containing the line break. Also set m_startsAtEmptyLine to true.
        (WebCore::DeleteSelectionCommand::mergeParagraphs): If
        m_startsAtEmptyLine is true, create a placeholder BR to serve as the
        merge destination.
        * editing/DeleteSelectionCommand.h:

LayoutTests:

        Reviewed by Darin Adler.

        - another test for <rdar://problem/6617298> Typing delete on an unquoted
          blank line unquotes the preceding, quoted blank line

        * editing/deleting/type-delete-after-quote-2-expected.txt: Added.
        * editing/deleting/type-delete-after-quote-2.html: Added.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@43154 268f45cc-cd09-0410-ab3c-d52691b4dbfc