Add a mojom/StructTrait for display::Display.

services/ui/public/interfaces/BUILD.gn

 # Copyright 2014 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.
 
 import("//mojo/public/tools/bindings/mojom.gni")
+import("//testing/test.gni")
 
 mojom("interfaces") {
   sources = [
     "accelerator_registrar.mojom",
     "accessibility_manager.mojom",
     "animations.mojom",
     "channel_handle.mojom",
     "clipboard.mojom",
     "command_buffer.mojom",
     "cursor.mojom",
@@ skipping 22 matching lines @@
 
   public_deps = [
     "//cc/ipc:interfaces",
     "//gpu/ipc/common:interfaces",
     "//ui/events/mojo:interfaces",
     "//ui/gfx/geometry/mojo",
     "//ui/gfx/mojo",
     "//ui/platform_window/mojo:interfaces",
   ]
 }
+
+test("ui_struct_traits_unittests") {
+  sources = [
+    "display/display_struct_traits_unittest.cc",
+  ]
+
+  deps = [
+    "//base",
+    "//base/test:test_support",
+    "//mojo/edk/test:run_all_unittests",
+    "//services/ui/public/interfaces/display:test_interfaces",
+    "//testing/gtest",
+    "//ui/display/types",
+    "//ui/gfx:test_support",
+  ]
+}