[USB internals WebUi] Fix a problem in transition to mojom-lite

The file device_manager_test.mojom-lite.js is updated so add a '$' here
to make it working.

Bug: 931809
Change-Id: I3d1b3c469743bdce45c511079d833c1401cf7f2f
Reviewed-on: https://chromium-review.googlesource.com/c/1479093
Auto-Submit: Nancy Li <nancyly@google.com>
Commit-Queue: Reilly Grant <reillyg@chromium.org>
Reviewed-by: Reilly Grant <reillyg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#633858}

chrome/browser/resources/usb_internals/usb_internals.js

@@ -14,7 +14,7 @@ cr.define('usb_internals', function() {
 
       const pageHandler = mojom.UsbInternalsPageHandler.getProxy();
       this.usbManagerTest = new device.mojom.UsbDeviceManagerTestProxy;
-      pageHandler.bindTestInterface(this.usbManagerTest.createRequest());
+      pageHandler.bindTestInterface(this.usbManagerTest.$.createRequest());
 
       cr.ui.decorate('tabbox', cr.ui.TabBox);
       $('add-test-device-form').addEventListener('submit', (event) => {