WebXR depth: add OT token to depth API samples

Change-Id: I90e2042346f60df180f1e7a5d310ef945e40f44f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2521222
Commit-Queue: Klaus Weidner <klausw@chromium.org>
Auto-Submit: Piotr Bialecki <bialpio@chromium.org>
Reviewed-by: Klaus Weidner <klausw@chromium.org>
Cr-Commit-Position: refs/heads/master@{#824623}

third_party/webxr_test_pages/webxr-samples/proposals/phone-ar-depth-gpu.html

@@ -26,6 +26,8 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
     <meta name='mobile-web-app-capable' content='yes'>
     <meta name='apple-mobile-web-app-capable' content='yes'>
 
+    <meta http-equiv="origin-trial" content="Ak33Pb+/wTIeP0Pih/o6Fh24UKfNcnp2BhFaMKv5cCS4a9/OXyngyq+QMK2QGlIQqye//UVrefnJ5VMM0gO8UwwAAABaeyJvcmlnaW4iOiJodHRwczovL3N0b3JhZ2UuZ29vZ2xlYXBpcy5jb206NDQzIiwiZmVhdHVyZSI6IldlYlhSRGVwdGgiLCJleHBpcnkiOjE2MDgyMjc4MjB9">
+
     <title>AR Depth API</title>
 
     <link href='../css/common.css' rel='stylesheet'></link>

third_party/webxr_test_pages/webxr-samples/proposals/phone-ar-depth.html

@@ -26,6 +26,8 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
     <meta name='mobile-web-app-capable' content='yes'>
     <meta name='apple-mobile-web-app-capable' content='yes'>
 
+    <meta http-equiv="origin-trial" content="Ak33Pb+/wTIeP0Pih/o6Fh24UKfNcnp2BhFaMKv5cCS4a9/OXyngyq+QMK2QGlIQqye//UVrefnJ5VMM0gO8UwwAAABaeyJvcmlnaW4iOiJodHRwczovL3N0b3JhZ2UuZ29vZ2xlYXBpcy5jb206NDQzIiwiZmVhdHVyZSI6IldlYlhSRGVwdGgiLCJleHBpcnkiOjE2MDgyMjc4MjB9">
+
     <title>AR Depth API</title>
 
     <link href='../css/common.css' rel='stylesheet'></link>