Add vr feature policy

This CL enables vr feature policy. So that, if you want to disable vr within
your application, you can delivering the following HTTP response header:
Feature-Policy: vr 'none'
If you want to enable vr for all frames(including cross-origin iframes),
delivering this:
Feature-Policy: vr *
If you want to enable vr just for your own origin, delivering this:
Feature-Policy: vr 'self'

To request vr for iframes, you can
<iframe src="" allow="vr"></iframe> to grant vr to this iframe.

Bug: 666767
Change-Id: I48d7accf8553d6a9ac19d9f41dbbce2ff9934579
Reviewed-by: Ian Vollick <>
Reviewed-by: Michael Thiessen <>
Reviewed-by: Daniel Cheng <>
Reviewed-by: Brandon Jones <>
Reviewed-by: Ian Clelland <>
Commit-Queue: Biao She <>
Cr-Commit-Position: refs/heads/master@{#498674}
13 files changed