Reviewed by Tony Chang.

        dump-as-markup conversion: editing/pasteboard/paste-text-at-tabspan-001.html and paste-text-at-tabspan-002.html
        https://bugs.webkit.org/show_bug.cgi?id=58081

        Converted paste-text-at-tabspan-001.html and paste-text-at-tabspan-002.html to dump-as-markup tests.
        Also explained what to expect in each test.

        * editing/pasteboard/paste-text-at-tabspan-001-expected.txt: Added.
        * editing/pasteboard/paste-text-at-tabspan-001.html:
        * editing/pasteboard/paste-text-at-tabspan-002-expected.txt: Added.
        * editing/pasteboard/paste-text-at-tabspan-002.html:
        * platform/chromium-linux/editing/pasteboard/paste-text-at-tabspan-001-expected.checksum: Removed.
        * platform/chromium-linux/editing/pasteboard/paste-text-at-tabspan-001-expected.png: Removed.
        * platform/chromium-linux/editing/pasteboard/paste-text-at-tabspan-002-expected.checksum: Removed.
        * platform/chromium-linux/editing/pasteboard/paste-text-at-tabspan-002-expected.png: Removed.
        * platform/chromium-win/editing/pasteboard/paste-text-at-tabspan-001-expected.checksum: Removed.
        * platform/chromium-win/editing/pasteboard/paste-text-at-tabspan-001-expected.png: Removed.
        * platform/chromium-win/editing/pasteboard/paste-text-at-tabspan-001-expected.txt: Removed.
        * platform/chromium-win/editing/pasteboard/paste-text-at-tabspan-002-expected.checksum: Removed.
        * platform/chromium-win/editing/pasteboard/paste-text-at-tabspan-002-expected.png: Removed.
        * platform/chromium-win/editing/pasteboard/paste-text-at-tabspan-002-expected.txt: Removed.
        * platform/gtk/editing/pasteboard/paste-text-at-tabspan-001-expected.checksum: Removed.
        * platform/gtk/editing/pasteboard/paste-text-at-tabspan-001-expected.png: Removed.
        * platform/gtk/editing/pasteboard/paste-text-at-tabspan-001-expected.txt: Removed.
        * platform/gtk/editing/pasteboard/paste-text-at-tabspan-002-expected.checksum: Removed.
        * platform/gtk/editing/pasteboard/paste-text-at-tabspan-002-expected.png: Removed.
        * platform/gtk/editing/pasteboard/paste-text-at-tabspan-002-expected.txt: Removed.
        * platform/mac/editing/pasteboard/paste-text-at-tabspan-001-expected.checksum: Removed.
        * platform/mac/editing/pasteboard/paste-text-at-tabspan-001-expected.png: Removed.
        * platform/mac/editing/pasteboard/paste-text-at-tabspan-001-expected.txt: Removed.
        * platform/mac/editing/pasteboard/paste-text-at-tabspan-002-expected.checksum: Removed.
        * platform/mac/editing/pasteboard/paste-text-at-tabspan-002-expected.png: Removed.
        * platform/mac/editing/pasteboard/paste-text-at-tabspan-002-expected.txt: Removed.
        * platform/qt/editing/pasteboard/paste-text-at-tabspan-001-expected.txt: Removed.
        * platform/qt/editing/pasteboard/paste-text-at-tabspan-002-expected.checksum: Removed.
        * platform/qt/editing/pasteboard/paste-text-at-tabspan-002-expected.png: Removed.
        * platform/qt/editing/pasteboard/paste-text-at-tabspan-002-expected.txt: Removed.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@83343 268f45cc-cd09-0410-ab3c-d52691b4dbfc