fix always 0% for chrome61~

why?
abolition document.body.scrollTop

Interoperable body/documentElement scroll behavior
https://www.chromestatus.com/feature/6386758136627200

download
https://chrome.google.com/webstore/detail/lcmhhnccfbeinmgacmomlkcahidhjifb/publish-accepted?hl=ja

renamed app name

download
https://chrome.google.com/webstore/detail/lcmhhnccfbeinmgacmomlkcahidhjifb/publish-accepted?hl=ja

chrome web store published

download
https://chrome.google.com/webstore/detail/lcmhhnccfbeinmgacmomlkcahidhjifb/publish-accepted?hl=ja