Revert "Add support for secondary views in WebXR"

This reverts commit 3e18562f.

Reason for revert:
Findit (https://goo.gl/kROfz5) identified this CL at revision 3e18562f as
the culprit for failures in the continuous build including:

Sample Failed Build: https://ci.chromium.org/b/8825245329676287921
Sample Failed Step: compile

If it is a false positive, please report it at https://bugs.chromium.org/p/chromium/issues/entry?status=Available&comment=Datastore+key+for+the+culprit+entity%3A+chromium.googlesource.com%2Fchromium%2Fsrc%2Frefs%2Fheads%2Fmain%2F3e18562ffed33aa145e4946121c78360b2f6a9da&labels=Test-Findit-Wrong&components=Tools%3ETest%3EFindIt&summary=Wrongly+blame+3e18562ffed33aa145e4946121c78360b2f6a9da

Original change's description:
> Add support for secondary views in WebXR
> 
> This change adds support for requesting secondary views in WebXR.
> Secondary views can be requested by passing in 'secondary-views'
> to requestSession. With this enabled, an arbitrary number of
> secondary views can be exposed from the XR runtime on each frame.
> 
> This change also implements secondary views in the OpenXR backend,
> supporting the first-person observer view configuration. Secondary views
> in OpenXR are only exposed to WebXR only when they are active (such as
> when the camera feed is being captured) and requested by WebXR.
> 
> Change-Id: Icb6a886e3f3b907f0c619bce5cf1f1481fb38a44
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3235583


> Reviewed-by: danakj chromium <danakj@chromium.org>
> Reviewed-by: Alexander Cooper <alcooper@chromium.org>
> Reviewed-by: Rafael Cintron <rafael.cintron@microsoft.com>
> Commit-Queue: Patrick To <patrto@microsoft.com>
> Cr-Commit-Position: refs/heads/main@{#958008}


Change-Id: Ib5ede98da34f2e8012e8987152df7877054b5cfb
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3382921


Owners-Override: Theodore Olsauskas-Warren <sauski@google.com>
Reviewed-by: Sean Harrison <harrisonsean@chromium.org>
Commit-Queue: Theodore Olsauskas-Warren <sauski@google.com>
Cr-Commit-Position: refs/heads/main@{#958031}