Mark several tests under virtual/windows-directwrite/fast/ as NeedsManualRebaseline after r171226

They started failing with IMAGE diff after r171226.

http://test-results.appspot.com/dashboards/flakiness_dashboard.html#group=%40ToT%20Blink&tests=virtual/windows-directwrite/fast/text/basic/generic-family-reset.html,virtual/windows-directwrite/fast/text/drawBidiText.html,virtual/windows-directwrite/fast/text/international/bidi-listbox-atsui.html,virtual/windows-directwrite/fast/text/international/bidi-listbox.html,virtual/windows-directwrite/fast/text/international/bidi-menulist.html,virtual/windows-directwrite/fast/text/textIteratorNilRenderer.html

BUG=356780
TBR=eae@chromium.org

Review URL: https://codereview.chromium.org/232943004

git-svn-id: svn://svn.chromium.org/blink/trunk@171276 bbb929c8-8fbe-4397-9dbb-9b2b20218538