The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/ff7acdec99021e413764c6cc827226979a144638

commit ff7acdec99021e413764c6cc827226979a144638
Author: Christopher Grant <cjgrant@chromium.org>
Date: Thu Apr 05 15:22:18 2018

VR: Remove obsolete full screen toast

Latest UX spec drops this element in favor of controller tooltips.

BUG= 829059 

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;master.tryserver.chromium.linux:linux_vr;master.tryserver.chromium.win:win_optional_gpu_tests_rel
Change-Id: I933a6c0e6ba2877a13777200a9774328ea04a826
Reviewed-on: https://chromium-review.googlesource.com/996525
Reviewed-by: Biao She <bshe@chromium.org>
Commit-Queue: Christopher Grant <cjgrant@chromium.org>
Cr-Commit-Position: refs/heads/master@{#548426}
[modify] https://crrev.com/ff7acdec99021e413764c6cc827226979a144638/chrome/app/generated_resources.grd
[modify] https://crrev.com/ff7acdec99021e413764c6cc827226979a144638/chrome/browser/vr/elements/ui_element_name.cc
[modify] https://crrev.com/ff7acdec99021e413764c6cc827226979a144638/chrome/browser/vr/elements/ui_element_name.h
[modify] https://crrev.com/ff7acdec99021e413764c6cc827226979a144638/chrome/browser/vr/ui_scene_creator.cc
[modify] https://crrev.com/ff7acdec99021e413764c6cc827226979a144638/chrome/browser/vr/ui_unittest.cc

Fix verified in build 67.0.3396.29 beta.  Looks good.