This is chrome bug 28768 (http://crbug.com/28768). In the font fallback, Chrome on Windows uses MS PGothic for JA chrome, Gulim for KO chrome and Simsun for both zh_Hans and zh_Hant chrome. Traditional Chinese Chrome users prefer PMingliu. In terms of character coverage, Simsun and PMingliu are comparable.
Created attachment 49406 [details] patch (a few liner)
Comment on attachment 49406 [details] patch (a few liner) Clearing flags on attachment: 49406 Committed r55223: <http://trac.webkit.org/changeset/55223>
All reviewed patches have been landed. Closing bug.