GitLab

Set Battery Status API status to stable in blink. We have
implementations for all platforms supported by blink now,
i.e. on Android, Windows, Linux, ChromeOS and Mac.

BUG=122593
TEST=http://jsbin.com/battery-status-test

Review URL: https://codereview.chromium.org/451583003

git-svn-id: svn://svn.chromium.org/blink/trunk@180296 bbb929c8-8fbe-4397-9dbb-9b2b20218538