Add the first layout tests for WebVR to test navigator.getVRDisplays with mocked vr_service mojo in…

third_party/WebKit/LayoutTests/vr/resources/mock-vr-service.js

+'use strict';
+
+let mockVRService = loadMojoModules(
+    'mockVRService',
+    ['mojo/public/js/bindings',
+     'mojo/public/js/connection',

[yzshen1, 2017/01/03 22:29:05]

Please note that "connection" is deprecated and being removed soon.

[bsheedy, 2017/01/03 22:39:06]

What do you suggest using in its place? Or should using the solution you
suggested below handle this for us?

[Lei Lei, 2017/01/03 22:40:35]

With bindings.BindingSet, connection is not needed anymore.

+     'mojo/public/js/router',
+     'device/vr/vr_service.mojom',
+    ]).then(mojo => {
+  let [bindings, connection, router, vr_service] = mojo.modules;
+
+  class MockVRDisplay extends vr_service.VRDisplay.stubClass {
+    constructor(interfaceProvider) {
+      super();
+      interfaceProvider.addInterfaceOverrideForTesting(
+          vr_service.VRDisplay.name,
+          handle => this.connect_(handle));
+    }
+
+    connect_(handle) {
+      this.router_ = new router.Router(handle);

[yzshen1, 2017/01/03 22:29:05]

Please don't use router directly, this doesn't do validation of incoming
messages properly.

An example of the correct/recommended way:
https://codesearch.chromium.org/chromium/src/third_party/WebKit/LayoutTests/s...

[bsheedy, 2017/01/03 22:39:06]

I'll look into changing this, then.

[Lei Lei, 2017/01/03 22:40:35]

Thanks for fixing it!

+      this.router_.setIncomingReceiver(this);
+    }
+  }
+
+  class MockVRService extends vr_service.VRService.stubClass {
+    constructor(interfaceProvider) {
+      super();
+      interfaceProvider.addInterfaceOverrideForTesting(
+          vr_service.VRService.name,
+          handle => this.connect_(handle));
+      this.vrDisplays_ = null;
+    }
+
+    connect_(handle) {
+      this.router_ = new router.Router(handle);
+      this.router_.setIncomingReceiver(this);
+    }
+
+    setVRDisplays(displays) {
+      this.vrDisplays_ = displays;
+    }
+
+    setClient(client) {
+      if (this.vrDisplays_ != null) {
+        this.vrDisplays_.forEach(display => {
+          var displayPtr = new vr_service.VRDisplayPtr();
+          var request = bindings.makeRequest(displayPtr);
+          var binding = new bindings.Binding(
+              vr_service.VRDisplay,
+              new MockVRDisplay(mojo.frameInterfaces), request);
+          var client_handle = new bindings.InterfaceRequest(
+            connection.bindProxy(proxy => {}, vr_service.VRDisplayClient));
+          client.onDisplayConnected(displayPtr, client_handle, display);
+        });
+        return Promise.resolve(
+            {numberOfConnectedDevices: this.vrDisplays_.length});
+      }
+      return Promise.resolve({numberOfConnectedDevices: 0});
+    }
+  }
+
+  return new MockVRService(mojo.frameInterfaces);
+});
+
+function vr_test(func, vrDisplays, name, properties) {
+  promise_test(t => mockVRService.then((service) => {
+    service.setVRDisplays(vrDisplays);
+    return func();
+  }), name, properties);
+}
+
+