Merge pull request #4700 from ArekSredzki/async-document-hidden
authorCheng Zhao <zcbenz@gmail.com>
Fri, 11 Mar 2016 01:19:06 +0000 (10:19 +0900)
committerCheng Zhao <zcbenz@gmail.com>
Fri, 11 Mar 2016 01:19:06 +0000 (10:19 +0900)
Cache browser visibility state & emit visibilitychange event on change


Trivial merge