Assign names to VR UI elements for debugging and test.

chrome/browser/resources/vr_shell/vr_shell_ui_api.js

Index: chrome/browser/resources/vr_shell/vr_shell_ui_api.js
diff --git a/chrome/browser/resources/vr_shell/vr_shell_ui_api.js b/chrome/browser/resources/vr_shell/vr_shell_ui_api.js
index 05204e93e0e6297336c9b9e666d84c7e1d35c780..366344968274cfbb73c0395fa34603027f177999 100644
--- a/chrome/browser/resources/vr_shell/vr_shell_ui_api.js
+++ b/chrome/browser/resources/vr_shell/vr_shell_ui_api.js
@@ -214,6 +214,14 @@ api.UiElementUpdate = class {
   }
 
   /**
+   * Set the name of the element. This name is used for debug and testing.
+   * @param {string} name
+   */
+  setName(name) {
+    this.properties['name'] = name;
+  }
+
+  /**
    * Specify a parent for this element. If set, this element is positioned
    * relative to its parent element, rather than absolutely. This allows
    * elements to automatically move with a parent.