The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/4cdea8db5c2f1067b3b26154c3e2abd6780e4466

commit 4cdea8db5c2f1067b3b26154c3e2abd6780e4466
Author: Tibor Goldschwendt <tiborg@chromium.org>
Date: Thu May 10 15:46:46 2018

[vr] Add runtime flag to enable tabs view

Bug:  840931 
Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel;luci.chromium.try:linux_optional_gpu_tests_rel;luci.chromium.try:mac_optional_gpu_tests_rel;luci.chromium.try:win_optional_gpu_tests_rel;master.tryserver.chromium.linux:linux_vr
Change-Id: I7e1b336aeed1648fcbe01ae479f486e0b8ba5ac4
Reviewed-on: https://chromium-review.googlesource.com/1053065
Commit-Queue: Tibor Goldschwendt <tiborg@chromium.org>
Reviewed-by: Michael Thiessen <mthiesse@chromium.org>
Cr-Commit-Position: refs/heads/master@{#557530}
[modify] https://crrev.com/4cdea8db5c2f1067b3b26154c3e2abd6780e4466/chrome/browser/about_flags.cc
[modify] https://crrev.com/4cdea8db5c2f1067b3b26154c3e2abd6780e4466/chrome/browser/android/chrome_feature_list.cc
[modify] https://crrev.com/4cdea8db5c2f1067b3b26154c3e2abd6780e4466/chrome/browser/android/chrome_feature_list.h
[modify] https://crrev.com/4cdea8db5c2f1067b3b26154c3e2abd6780e4466/chrome/browser/android/vr/vr_shell.cc
[modify] https://crrev.com/4cdea8db5c2f1067b3b26154c3e2abd6780e4466/chrome/browser/flag_descriptions.cc
[modify] https://crrev.com/4cdea8db5c2f1067b3b26154c3e2abd6780e4466/chrome/browser/flag_descriptions.h
[modify] https://crrev.com/4cdea8db5c2f1067b3b26154c3e2abd6780e4466/chrome/browser/vr/testapp/vr_test_context.cc
[modify] https://crrev.com/4cdea8db5c2f1067b3b26154c3e2abd6780e4466/chrome/browser/vr/ui.h
[modify] https://crrev.com/4cdea8db5c2f1067b3b26154c3e2abd6780e4466/tools/metrics/histograms/enums.xml

Can activate tabs view now through chrome://flags/#vr-browsing-tabs-view.