Enabel webxr with html argument.

Check comments in `meshcat.html` for more info on how to use.

Author: WawasCode

geometry/meshcat.html

@@ -170,6 +170,30 @@
     make_connection(url, reconnect_ms);
     <!-- CONNECTION BLOCK END -->
 
+    const webxrMode = urlParams.get('webxr');
+    if (webxrMode) {
+      if (webxrMode === "vr") {
+        viewer.handle_command({
+          type: "enable_webxr",
+          mode: "vr"
+        });
+      } else if (webxrMode === "ar") {
+        viewer.handle_command({
+          type: "enable_webxr",
+          mode: "ar"
+        });
+      }
+    }
+
+    const controllerMode = urlParams.get('controller');
+    if (controllerMode === "on") {
+      viewer.handle_command({
+        type: "visualize_vr_controller"
+      });
+    }
+
+
+
   </script>
 
   <style>

tools/workspace/meshcat/repository.bzl

@@ -10,8 +10,8 @@ def meshcat_repository(
         Updating this commit requires local testing; see
         drake/tools/workspace/meshcat/README.md for details.
         """,
-        commit = "44eac463725f048c47debfe34d3f935d01aa6bac",
-        sha256 = "7ac5e9fdcc407abb4770bad1cee849de939f1dc856ef38d601a1982abec68ac3",  # noqa
+        commit = "c788d692d62bf63408be3a127a6288c9845b4325",
+        sha256 = "0ac908b62cc77fcb9b0fc9fa55e04eeee3eda3e94045e85ccef556cb0cb6271a",  # noqa
         build_file = ":package.BUILD.bazel",
         mirrors = mirrors,
     )