Removing Blink>WebVR component and assigning to Blink>WebXR 

Removing Blink>WebVR component and assigning to Blink>WebXR 

Some additional notes regarding user experience on Android N (Pixel) M71:

1. I enabled the #webxr, #webxr-gamepad-support, and #webxr-hit-test flags from chrome://flags.

Expected: Since AR isn't supported on this device, maybe we shouldn't even have the #webxr-hit-test appear on the flags page?

2. I went to https://immersive-web.github.io/webxr-samples/proposals/phone-ar-hit-test.html and an infobar appeared telling me the site requires me to install "ARCore by Google" in order to work.

Expected: Since the device isn't supported anyways, installing ARCore isn't necessary. So I wouldn't expect a prompt to install it.

3. After installing ARCore, I clicked on the Start AR button. Nothing happened.

Expected: The button should remain disabled in it's "not supported" state.

@billorr, I'm addressing original issue by moving OS version check to ARCoreDeviceProvider.


@dbbrooks
RE 1: I think we still want the flags to be present - the AR support is not there, but we want to control the presence of API entry points.

RE 2: I couldn't reproduce this behavior (Android 7.1.2, Chrome 70.0.3538.80).

RE 3: I see the same behavior - when clicking "Start AR" button, there is no visible action happening, although the promise to request a session from the device is throwing an exception. This seems like a bug - device.supportsSession(...) was resolving fine but device.requestSession(...) with same parameters is being rejected. I'll open a new bug to track this issue.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/d6456ac6874d409bdcf88c197c6673373aaa73c1

commit d6456ac6874d409bdcf88c197c6673373aaa73c1
Author: Piotr Bialecki <bialpio@chromium.org>
Date: Mon Nov 19 22:20:54 2018

Move OS version check for AR Core from java to native

Additionally, add a call to check AR Core support from ArCoreDeviceProvider.

This will also fix an issue where not all options for supportsSession
call were being passed.

R=billorr@chromium.org, btebbs@chromium.org, mthiesse@chromium.org

Bug:  852607 
Change-Id: I3e407fd001368cbdead0dbf271ee3bdca8188019
Reviewed-on: https://chromium-review.googlesource.com/c/1341025
Commit-Queue: Piotr Bialecki <bialpio@chromium.org>
Reviewed-by: Klaus Weidner <klausw@chromium.org>
Reviewed-by: Bill Orr <billorr@chromium.org>
Reviewed-by: Michael Thiessen <mthiesse@chromium.org>
Cr-Commit-Position: refs/heads/master@{#609465}
[modify] https://crrev.com/d6456ac6874d409bdcf88c197c6673373aaa73c1/chrome/android/java/src/org/chromium/chrome/browser/vr/ArCoreJavaUtils.java
[modify] https://crrev.com/d6456ac6874d409bdcf88c197c6673373aaa73c1/chrome/browser/android/vr/arcore_device/arcore_device_provider.cc
[modify] https://crrev.com/d6456ac6874d409bdcf88c197c6673373aaa73c1/chrome/browser/android/vr/arcore_device/arcore_java_utils.cc
[modify] https://crrev.com/d6456ac6874d409bdcf88c197c6673373aaa73c1/chrome/browser/android/vr/arcore_device/arcore_shim.cc
[modify] https://crrev.com/d6456ac6874d409bdcf88c197c6673373aaa73c1/chrome/browser/android/vr/arcore_device/arcore_shim.h
[modify] https://crrev.com/d6456ac6874d409bdcf88c197c6673373aaa73c1/third_party/blink/renderer/modules/xr/xr_device.cc