yfriedman says this will still show up on M67 pending some level of engagement with the site.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/1bf8f8002c2d816bad3bead3d0617db18f3b4b09

commit 1bf8f8002c2d816bad3bead3d0617db18f3b4b09
Author: Michael Thiessen <mthiesse@chromium.org>
Date: Wed May 09 18:22:29 2018

Don't show AppBanner while in VR.

Note that this doesn't handle the case where the banner is already open
when entering VR. That's complicated and I'm not going to try to merge
a fix for that back to M67.

(This CL is targeted for M67)

Bug:  840811 
Change-Id: I9e4daba4baeed7aeb8f5b841fdb7acb1f7872ff7
Reviewed-on: https://chromium-review.googlesource.com/1052211
Commit-Queue: Michael Thiessen <mthiesse@chromium.org>
Reviewed-by: Yaron Friedman <yfriedman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#557248}
[modify] https://crrev.com/1bf8f8002c2d816bad3bead3d0617db18f3b4b09/chrome/android/java/src/org/chromium/chrome/browser/banners/AppBannerManager.java

Verified in Canary.

CL is trivial and exclusive to VR, so should be safe to merge.

This bug requires manual review: M67 has already been promoted to the beta branch, so this requires manual review
Please contact the milestone owner if you have questions.
Owners: cmasso@(Android), cmasso@(iOS), kbleicher@(ChromeOS), govind@(Desktop)

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/8e1951211d8a42024463ff44029f325b9a4b7674

commit 8e1951211d8a42024463ff44029f325b9a4b7674
Author: Michael Thiessen <mthiesse@chromium.org>
Date: Thu May 10 19:32:44 2018

Don't show AppBanner while in VR.

Note that this doesn't handle the case where the banner is already open
when entering VR. That's complicated and I'm not going to try to merge
a fix for that back to M67.

(This CL is targeted for M67)

TBR=mthiesse@chromium.org

(cherry picked from commit 1bf8f8002c2d816bad3bead3d0617db18f3b4b09)

Bug:  840811 
Change-Id: I9e4daba4baeed7aeb8f5b841fdb7acb1f7872ff7
Reviewed-on: https://chromium-review.googlesource.com/1052211
Commit-Queue: Michael Thiessen <mthiesse@chromium.org>
Reviewed-by: Yaron Friedman <yfriedman@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#557248}
Reviewed-on: https://chromium-review.googlesource.com/1054381
Reviewed-by: Michael Thiessen <mthiesse@chromium.org>
Cr-Commit-Position: refs/branch-heads/3396@{#553}
Cr-Branched-From: 9ef2aa869bc7bc0c089e255d698cca6e47d6b038-refs/heads/master@{#550428}
[modify] https://crrev.com/8e1951211d8a42024463ff44029f325b9a4b7674/chrome/android/java/src/org/chromium/chrome/browser/banners/AppBannerManager.java

Verified on builds 68.3427.0 Canary and 67.0.3396.46 beta.
Fix for beta is in build 67.0.3396.43, build .46+ is being reviewed for release to beta soon.
The AppBanner is no longer visible in VR thus there is no access to this Add to Home Screen menu item.  Looks good.