Yesterday I noticed slightly improvement at latest Chromium for mac(also latest Chrome for mac). Finally it supported Adobe Flash Plugin and Japanese input inside HTML content!! It's exciting. One of Chromium advantage against Safari is that Chromium introduced userscript(Greasemonkey) functionality. You can extend your favorite site using JavaScript. I memorize how to enable userscript on Chromium here.

1. Open terminal
2. Run Chromium with argument '--enable-user-scripts' like this
   $  /Applications/Chromium.app/Contents/MacOS/Chromium --enable-user-scripts
3. Create 'User Scripts' directory and store your favorite script under there as extension '.user.js'.
   ~/Library/Application Support/Chromium/Default/User Scripts