Workaround for WMR UserPresence bug

Provides a workaround for an issue with some versions of Windows Mixed
Reality where the HolographicSpaceUserPresence will only ever report
Absent or PresentPassive, and never PresentActive. We would ideally like
to map PresentPassive to the WebXR state "visible-blurred", as their
meaning is very close, but until this bug is fixed we'll need to force
it to map to "visible" so that content runs correctly.

Bug: 1016907
Change-Id: Icbec972fd6b62d1892609f8cf84ddf9f8190bc44
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1873157Reviewed-by: Alexander Cooper <alcooper@chromium.org>
Commit-Queue: Brandon Jones <bajones@chromium.org>
Cr-Commit-Position: refs/heads/master@{#708372}

device/vr/windows_mixed_reality/mixed_reality_renderloop.cc

@@ -427,7 +427,11 @@ void MixedRealityRenderLoop::UpdateVisibilityState() {
     // and the headset is being worn, but a modal dialog is capturing input.
     case HolographicSpaceUserPresence::
         HolographicSpaceUserPresence_PresentPassive:
-      SetVisibilityState(device::mojom::XRVisibilityState::VISIBLE_BLURRED);
+      // TODO(1016907): Should report VISIBLE_BLURRED, but changed to VISIBLE to
+      // work around an issue in some versions of Windows Mixed Reality which
+      // only report PresentPassive and never PresentActive. Should be reverted
+      // after the Windows fix has been widely released.
+      SetVisibilityState(device::mojom::XRVisibilityState::VISIBLE);
       return;
     // Indicates that the browsers immersive content is not visible in the
     // headset or the user is not wearing the headset.