Merge pull request #4 from ygoto3/userTimingApiTranslation

User Timing API: Understanding your Web App
Merge branch 'master' of https://github.com/html5rocks/www.html5rocks.com
Merge branch 'master' of https://github.com/html5rocks/www.html5rocks.com
translated "Debugging Asynchronous JavaScript with Chrome DevTools" into Japanese
Merge branch 'master' of https://github.com/html5rocks/www.html5rocks.com
translated "Debugging Asynchronous JavaScript with Chrome DevTools" into Japanese
Merge branch 'async-call-stack-japanese-translation' of https://github.com/ygoto3/www.html5rocks.com into async-call-stack-japanese-translation
corrected the incorrect spilling
Merge pull request #1194 from ygoto3/async-call-stack-japanese-translation

translated "Debugging Asynchronous JavaScript with Chrome DevTools" into Japanese