The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/bd3a5c1291959abcb9b70381e63156d6ae234e5a

commit bd3a5c1291959abcb9b70381e63156d6ae234e5a
Author: tiborg <tiborg@chromium.org>
Date: Thu Apr 27 16:55:48 2017

Enters VrShell if WebVR page doesn not request present in vrdisplayactivate handler.

- Browser goes into VR Browsing Mode when the user inserts the phone into the headeset.
- Browser will then automatically go into presentation mode if page requests present in onvrdisplayactivate handler.
- In a follow-up CL, browser should tentatively go into presentation mode if page is listening for onvrdisplayactivate (and exit presentation if page does not request present).

BUG= 703315 

Review-Url: https://codereview.chromium.org/2850483003
Cr-Commit-Position: refs/heads/master@{#467714}

[modify] https://crrev.com/bd3a5c1291959abcb9b70381e63156d6ae234e5a/chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrShellDelegate.java

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/740768575325237705b0249460683fcf692bbd1e

commit 740768575325237705b0249460683fcf692bbd1e
Author: tiborg <tiborg@chromium.org>
Date: Tue May 02 01:33:13 2017

Tentatively goes into WebVR presentation mode if page listens to vrdisplayactivate.

- When the user puts the phone into the headset VR browser goes into WebVR presentation mode if the page listens to vrdisplayactivate.
- If the page does not request presentation in the vrdisplayactivate handler browser exits presentation and goes into VrShell.

BUG= 703315 

Review-Url: https://codereview.chromium.org/2844833005
Cr-Commit-Position: refs/heads/master@{#468526}

[modify] https://crrev.com/740768575325237705b0249460683fcf692bbd1e/chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrShellDelegate.java
[modify] https://crrev.com/740768575325237705b0249460683fcf692bbd1e/chrome/browser/android/vr_shell/vr_shell_delegate.cc
[modify] https://crrev.com/740768575325237705b0249460683fcf692bbd1e/chrome/browser/android/vr_shell/vr_shell_delegate.h
[modify] https://crrev.com/740768575325237705b0249460683fcf692bbd1e/device/vr/test/fake_vr_display_impl_client.h
[modify] https://crrev.com/740768575325237705b0249460683fcf692bbd1e/device/vr/vr_device.cc
[modify] https://crrev.com/740768575325237705b0249460683fcf692bbd1e/device/vr/vr_device.h
[modify] https://crrev.com/740768575325237705b0249460683fcf692bbd1e/device/vr/vr_display_impl.cc
[modify] https://crrev.com/740768575325237705b0249460683fcf692bbd1e/device/vr/vr_display_impl.h
[modify] https://crrev.com/740768575325237705b0249460683fcf692bbd1e/device/vr/vr_service.mojom
[modify] https://crrev.com/740768575325237705b0249460683fcf692bbd1e/third_party/WebKit/Source/modules/vr/VRDisplay.cpp
[modify] https://crrev.com/740768575325237705b0249460683fcf692bbd1e/third_party/WebKit/Source/modules/vr/VRDisplay.h