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 {
+
+class WaylandDisplayTest : public testing::Test {
+ public:
+  WaylandDisplayTest() : server(&mock_xdg_shell) {}
+
+  ~WaylandDisplayTest() override {}
+
+  void SetUp() override {
+    ASSERT_TRUE(server.Start());
+    EXPECT_CALL(mock_xdg_shell, UseUnstableVersion(XDG_SHELL_VERSION_CURRENT));
+    ASSERT_TRUE(display.Initialize());
+    wl_display_roundtrip(display.display());
+    initialized = true;
+  }
+
+  void TearDown() override {
+    if (initialized)
+      wl_display_roundtrip(display.display());
+  }
+
+ protected:
+  wl::MockXdgShell mock_xdg_shell;
+  wl::FakeServer server;
+  WaylandDisplay display;
+
+ private:
+  bool initialized = false;
+
+  DISALLOW_COPY_AND_ASSIGN(WaylandDisplayTest);
+};
+
+TEST_F(WaylandDisplayTest, Ping) {
+  xdg_shell_send_ping(server.xdg_shell(), 1234);
+  EXPECT_CALL(mock_xdg_shell, Pong(1234));
+  server.Flush();
+}
+
+}  // namespace ui