Revert "Remove usage of HMD devices as an inline provider"

This reverts commit 28bae1e221f99f4330a12d5af68fcdeaa28f6466.

Reason for revert: 939887,939901

Original change's description:
> Remove usage of HMD devices as an inline provider
> 
> Now that the inline identity space is always supported as per the spec
> we don't need to have GVR and other HMDs support the inline scenario.
> Until/unless we have support for orientation sensors on the platforms
> (which should support the stationary spatial reference spaces), we will
> simply use the identity space.
> 
> Bug: 891552
> Change-Id: Id9f56bb42f87dfac0c4a37878da9763ecbb5a5c7
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1490523
> Commit-Queue: Alexander Cooper <alcooper@chromium.org>
> Reviewed-by: Brian Sheedy <bsheedy@chromium.org>
> Reviewed-by: Brandon Jones <bajones@chromium.org>
> Reviewed-by: Bill Orr <billorr@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#638787}

TBR=bajones@chromium.org,bsheedy@chromium.org,billorr@chromium.org,alcooper@chromium.org

Change-Id: Ie45b8745aa4b4a4da3f5f4a2234affdeba07dd18
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 891552
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1512333
Reviewed-by: Bill Orr <billorr@chromium.org>
Commit-Queue: Bill Orr <billorr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#639110}
14 files changed