[VR Shell] Fix hidden elements being hit-testable.

chrome/browser/resources/vr_shell/vr_shell_ui.js

Index: chrome/browser/resources/vr_shell/vr_shell_ui.js
diff --git a/chrome/browser/resources/vr_shell/vr_shell_ui.js b/chrome/browser/resources/vr_shell/vr_shell_ui.js
index a6eedc1c17176e7827b40c024fb323788f347fc6..de421682b76de8b9c9d1a82e9c8b6d768d94cd5f 100644
--- a/chrome/browser/resources/vr_shell/vr_shell_ui.js
+++ b/chrome/browser/resources/vr_shell/vr_shell_ui.js
@@ -51,14 +51,14 @@ var vrShellUi = (function() {
       element.setTranslation(0, 0, -this.BROWSING_SCREEN_DISTANCE);
       this.elementId = ui.addElement(element);
 
-      // Place an invisible but hittable plane behind the content quad, to keep
-      // the reticle roughly planar with the content if near content.
+      // Place an invisible (fill none) but hittable plane behind the content
+      // quad, to keep the reticle roughly planar with the content if near
+      // content.
       let backPlane = new api.UiElement(0, 0, 0, 0);
-      backPlane.setVisible(false);
-      backPlane.setHitTestable(true);
       backPlane.setSize(1000, 1000);
       backPlane.setTranslation(0, 0, -0.01);
       backPlane.setParentId(this.elementId);
+      backPlane.setFill(new api.NoFill());
       ui.addElement(backPlane);
 
       this.updateState();