Reviewed by Sam Weinig.

        Add tests of font choices and metrics, to isolate those dependencies.

        https://bugs.webkit.org/show_bug.cgi?id=24566

        * fonts: Added.
        * fonts/cursive.html: Added.
        * fonts/default.html: Added.
        * fonts/fantasy.html: Added.
        * fonts/monospace.html: Added.
        * fonts/sans-serif.html: Added.
        * fonts/serif.html: Added.
        * platform/mac/fonts: Added.
        * platform/mac/fonts/cursive-expected.checksum: Added.
        * platform/mac/fonts/cursive-expected.png: Added.
        * platform/mac/fonts/cursive-expected.txt: Added.
        * platform/mac/fonts/default-expected.checksum: Added.
        * platform/mac/fonts/default-expected.png: Added.
        * platform/mac/fonts/default-expected.txt: Added.
        * platform/mac/fonts/fantasy-expected.checksum: Added.
        * platform/mac/fonts/fantasy-expected.png: Added.
        * platform/mac/fonts/fantasy-expected.txt: Added.
        * platform/mac/fonts/monospace-expected.checksum: Added.
        * platform/mac/fonts/monospace-expected.png: Added.
        * platform/mac/fonts/monospace-expected.txt: Added.
        * platform/mac/fonts/sans-serif-expected.checksum: Added.
        * platform/mac/fonts/sans-serif-expected.png: Added.
        * platform/mac/fonts/sans-serif-expected.txt: Added.
        * platform/mac/fonts/serif-expected.checksum: Added.
        * platform/mac/fonts/serif-expected.png: Added.
        * platform/mac/fonts/serif-expected.txt: Added.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@41955 268f45cc-cd09-0410-ab3c-d52691b4dbfc