ozone: Fix chromium-style method override warnings

BUG=417463
TEST=build with clang plugin

Review URL: https://codereview.chromium.org/885703002

Cr-Commit-Position: refs/heads/master@{#313561}

ui/events/ozone/chromeos/cursor_controller_unittest.cc

@@ -16,7 +16,7 @@ const gfx::AcceleratedWidget kTestWindow = 1;
 class CursorControllerTest : public testing::Test {
  public:
   CursorControllerTest() {}
-  virtual ~CursorControllerTest() {}
+  ~CursorControllerTest() override {}
 
   void TearDown() override {
     ui::CursorController::GetInstance()->ClearCursorConfigForWindow(

ui/events/ozone/evdev/touch_event_converter_evdev_unittest.cc

@@ -69,7 +69,7 @@ class MockDeviceEventDispatcherEvdev : public DeviceEventDispatcherEvdev {
   MockDeviceEventDispatcherEvdev(
       const base::Callback<void(const TouchEventParams& params)>& callback)
       : callback_(callback) {}
-  ~MockDeviceEventDispatcherEvdev() {}
+  ~MockDeviceEventDispatcherEvdev() override {}
 
   // DeviceEventDispatcherEvdev:
   void DispatchKeyEvent(const KeyEventParams& params) override {}

ui/events/ozone/layout/xkb/xkb_keyboard_layout_engine_unittest.cc

@@ -20,8 +20,8 @@ class VkTestXkbKeyCodeConverter : public XkbKeyCodeConverter {
   VkTestXkbKeyCodeConverter() {
     invalid_xkb_keycode_ = static_cast<xkb_keycode_t>(DomCode::NONE);
   }
-  virtual ~VkTestXkbKeyCodeConverter(){}
-  virtual xkb_keycode_t DomCodeToXkbKeyCode(DomCode dom_code) const override {
+  ~VkTestXkbKeyCodeConverter() override {}
+  xkb_keycode_t DomCodeToXkbKeyCode(DomCode dom_code) const override {
     return static_cast<xkb_keycode_t>(dom_code);
   }
 };
@@ -58,7 +58,7 @@ class VkTestXkbKeyboardLayoutEngine : public XkbKeyboardLayoutEngine {
       xkb_flag_map_.push_back(e);
     }
   }
-  virtual ~VkTestXkbKeyboardLayoutEngine() {}
+  ~VkTestXkbKeyboardLayoutEngine() override {}
 
   void SetEntry(const Entry* entry) { entry_ = entry; }
 
@@ -78,7 +78,7 @@ class VkTestXkbKeyboardLayoutEngine : public XkbKeyboardLayoutEngine {
   }
 
   // XkbKeyboardLayoutEngine overrides:
-  virtual bool XkbLookup(xkb_keycode_t xkb_keycode,
+  bool XkbLookup(xkb_keycode_t xkb_keycode,
                          xkb_mod_mask_t xkb_flags,
                          xkb_keysym_t* xkb_keysym,
                          base::char16* character) const override {
@@ -104,7 +104,7 @@ class VkTestXkbKeyboardLayoutEngine : public XkbKeyboardLayoutEngine {
 class XkbLayoutEngineVkTest : public testing::Test {
  public:
   XkbLayoutEngineVkTest() {}
-  virtual ~XkbLayoutEngineVkTest() {}
+  ~XkbLayoutEngineVkTest() override {}
 
   void SetUp() override {
     KeyboardLayoutEngineManager::SetKeyboardLayoutEngine(