Standardize usage of virtual/override/final specifiers in ash/.

ash/wm/always_on_top_controller_unittest.cc

Index: ash/wm/always_on_top_controller_unittest.cc
diff --git a/ash/wm/always_on_top_controller_unittest.cc b/ash/wm/always_on_top_controller_unittest.cc
index fe502e34db970c4ee2262f55e96b8af4cd35f7aa..535ed5ff2a6f14744a127e946a14b36368415e08 100644
--- a/ash/wm/always_on_top_controller_unittest.cc
+++ b/ash/wm/always_on_top_controller_unittest.cc
@@ -38,9 +38,9 @@ class TestLayoutManager : public WorkspaceLayoutManager {
   explicit TestLayoutManager(aura::Window* window)
       : WorkspaceLayoutManager(window), keyboard_bounds_changed_(false) {}
 
-  ~TestLayoutManager() {}
+  ~TestLayoutManager() override {}
 
-  virtual void OnKeyboardBoundsChanging(const gfx::Rect& bounds) override {
+  void OnKeyboardBoundsChanging(const gfx::Rect& bounds) override {
     keyboard_bounds_changed_ = true;
     WorkspaceLayoutManager::OnKeyboardBoundsChanging(bounds);
   }