ozone/platform/wayland: Add some tests

ui/ozone/platform/wayland/wayland_display_unittest.cc

+// 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.
+
+#include <wayland-server-core.h>
+#include <xdg-shell-unstable-v5-server-protocol.h>
+
+#include "testing/gtest/include/gtest/gtest.h"
+#include "ui/ozone/platform/wayland/fake_server.h"
+#include "ui/ozone/platform/wayland/wayland_display.h"
+
+namespace ui {
+
+TEST(WaylandDisplayTest, UseUnstableVersion) {
+  wl::FakeServer server;
+  EXPECT_CALL(*server.xdg_shell(),
+              UseUnstableVersion(XDG_SHELL_VERSION_CURRENT));
+  ASSERT_TRUE(server.Start());
+  WaylandDisplay display;
+  ASSERT_TRUE(display.Initialize());
+  wl_display_roundtrip(display.display());
+}
+
+TEST(WaylandDisplayTest, Ping) {
+  wl::FakeServer server;
+  ASSERT_TRUE(server.Start());
+  WaylandDisplay display;
+  ASSERT_TRUE(display.Initialize());
+  wl_display_roundtrip(display.display());
+
+  server.Pause();
+
+  xdg_shell_send_ping(server.xdg_shell()->resource(), 1234);
+  EXPECT_CALL(*server.xdg_shell(), Pong(1234));
+  server.Flush();
+
+  server.Resume();
+
+  wl_display_roundtrip(display.display());
+}
+
+}  // namespace ui