I think this is a dupe of issue 655199 (which was closed last Dec).

Chromium side changes are in, the only thing needed is server side config.  We can keep this bug open for that if we don't have anywhere else to track it.

Server side config landed in cl/155572486.

Marking this fixed.  There will be future iterations on the server side, but those will be tracked as part of the launch rollout.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/4f5fc1b7bd67d34a07bdeb5c69cd8ae101d65083

commit 4f5fc1b7bd67d34a07bdeb5c69cd8ae101d65083
Author: amp <amp@chromium.org>
Date: Mon May 15 16:35:53 2017

Enable VrShell by default on Android.

BUG= 715612 

Review-Url: https://codereview.chromium.org/2871053002
Cr-Commit-Position: refs/heads/master@{#471789}

[modify] https://crrev.com/4f5fc1b7bd67d34a07bdeb5c69cd8ae101d65083/content/public/common/content_features.cc
[modify] https://crrev.com/4f5fc1b7bd67d34a07bdeb5c69cd8ae101d65083/testing/variations/fieldtrial_testing_config.json