GitLab

Removes the unused linear/angular acceleration/velocity attributes from
VRPose.  These attributes were used for the head pose in WebVr, but are
not used in WebXr.

Also cleans up some WMR code that calculated similar values for the old
WebVr gamepad which was previously removed.

Bug: 1017843
Change-Id: Ie5c4259068c3c3b98d0eae4ab71fe92ffac76e86
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1903617Reviewed-by: Brandon Jones <bajones@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Commit-Queue: Alexander Cooper <alcooper@chromium.org>
Cr-Commit-Position: refs/heads/master@{#714067}