Undeprecate DocumentClear, CaptureEvents and ReleaseEvents

These are all specified for Document:
http://www.whatwg.org/specs/web-apps/current-work/multipage/obsolete.html#obsolete

There's no spec for Window, so split the CaptureEvents and ReleaseEvents counters.

BUG=none

Review URL: https://codereview.chromium.org/193443004

git-svn-id: svn://svn.chromium.org/blink/trunk@169054 bbb929c8-8fbe-4397-9dbb-9b2b20218538