Reviewed by Tony Chang.

        Modify Skipped files so that future css exclusions LayoutTests are
        skipped by default.

        [CSSExclusions] Add test and skip entries
        https://bugs.webkit.org/show_bug.cgi?id=63751

        * fast/exclusions/triangle-exclusion.html: Added.
        * platform/chromium/test_expectations.txt:
        * platform/gtk/Skipped:
        * platform/mac/Skipped:
        * platform/qt/Skipped:
        * platform/win/Skipped:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@90175 268f45cc-cd09-0410-ab3c-d52691b4dbfc