Add UseCounter for window.orientation usage.

It will help us decide if we should deprecate or remove
window.orientation when Screen Orientation API will start being used.

BUG=348003

Review URL: https://codereview.chromium.org/183853006

git-svn-id: svn://svn.chromium.org/blink/trunk@168728 bbb929c8-8fbe-4397-9dbb-9b2b20218538