Implement LatencyInfo StructTraits

ui/events/mojo/traits_test_service.mojom

Index: ui/events/mojo/traits_test_service.mojom
diff --git a/ui/events/mojo/traits_test_service.mojom b/ui/events/mojo/traits_test_service.mojom
new file mode 100644
index 0000000000000000000000000000000000000000..e47728d27ab886a195635e9ff7d217de9f33450d
--- /dev/null
+++ b/ui/events/mojo/traits_test_service.mojom
@@ -0,0 +1,21 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+module ui.mojom;
+
+import "ui/events/mojo/latency_info.mojom";
+
+interface TraitsTestService {
+  [Sync]
+  EchoInputCoordinate(InputCoordinate i) => (InputCoordinate pass);
+
+  [Sync]
+  EchoLatencyComponent(LatencyComponent l) => (LatencyComponent pass);
+
+  [Sync]
+  EchoLatencyComponentId(LatencyComponentId l) => (LatencyComponentId pass);
+
+  [Sync]
+  EchoLatencyInfo(LatencyInfo l) => (LatencyInfo pass);
+};