Investigating.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/9a8e0679d856c56547fc46e59eb20a07c2f14213

commit 9a8e0679d856c56547fc46e59eb20a07c2f14213
Author: Michael Thiessen <mthiesse@chromium.org>
Date: Thu Oct 12 22:19:35 2017

VR: Handle Surface recreation/context loss.

This CL prevents the crash that happens when the Android Surface is
destroyed for non-reprojected rendering. It re-initializes our GL
context and surfaces/textures to (almost) seamlessly stay in VR
through surface recreation.

Tests will come in a followup CL, as I'd like to get this crash fix
into M63, and tests will be complicated.

Bug:  773261 
Change-Id: I724d7405520bef83dbccd55672abf62431270ebd

# The bots are refusing to be triggered in this CL for some reason,
# and they've already passed other than cast_shell...

No-Try: true
Change-Id: I724d7405520bef83dbccd55672abf62431270ebd
Reviewed-on: https://chromium-review.googlesource.com/716664
Commit-Queue: Michael Thiessen <mthiesse@chromium.org>
Reviewed-by: Ian Vollick <vollick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#508503}
[modify] https://crrev.com/9a8e0679d856c56547fc46e59eb20a07c2f14213/chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrShellImpl.java
[modify] https://crrev.com/9a8e0679d856c56547fc46e59eb20a07c2f14213/chrome/browser/android/vr_shell/vr_shell.cc
[modify] https://crrev.com/9a8e0679d856c56547fc46e59eb20a07c2f14213/chrome/browser/android/vr_shell/vr_shell_gl.cc
[modify] https://crrev.com/9a8e0679d856c56547fc46e59eb20a07c2f14213/chrome/browser/vr/elements/exclusive_screen_toast.cc
[modify] https://crrev.com/9a8e0679d856c56547fc46e59eb20a07c2f14213/chrome/browser/vr/elements/textured_element.cc
[modify] https://crrev.com/9a8e0679d856c56547fc46e59eb20a07c2f14213/chrome/browser/vr/elements/ui_texture.cc
[modify] https://crrev.com/9a8e0679d856c56547fc46e59eb20a07c2f14213/chrome/browser/vr/elements/ui_texture.h