Update browser/vr OWNERS

Add self as test-related owner, add KlausW to subdirectory to guarantee
two OWNERS per file.

Change-Id: I6cfc7ec5b2486006829abf5784a5250f4a9bc4c4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1731775Reviewed-by: Brian Sheedy <bsheedy@chromium.org>
Reviewed-by: Klaus Weidner <klausw@chromium.org>
Commit-Queue: Alexander Cooper <alcooper@chromium.org>
Cr-Commit-Position: refs/heads/master@{#684147}

chrome/browser/vr/OWNERS

@@ -7,6 +7,7 @@ vollick@chromium.org
 klausw@chromium.org
 
 # Browser Test-related.
+alcooper@chromium.org
 bsheedy@chromium.org
 
 # TEAM: xr-dev@chromium.org

chrome/browser/vr/service/OWNERS

 alcooper@chromium.org
+klausw@chromium.org
 
 # TEAM: xr-dev@chromium.org
 # COMPONENT: Blink>WebXR