Standardize usage of virtual/override/final specifiers.

ash/shelf/shelf_tooltip_manager_unittest.cc

Index: ash/shelf/shelf_tooltip_manager_unittest.cc
diff --git a/ash/shelf/shelf_tooltip_manager_unittest.cc b/ash/shelf/shelf_tooltip_manager_unittest.cc
index 6312fdaeebf39fdc513afd1cdd68770fd0452277..d13d290752355ec786db6a87f58bfa212882e9de 100644
--- a/ash/shelf/shelf_tooltip_manager_unittest.cc
+++ b/ash/shelf/shelf_tooltip_manager_unittest.cc
@@ -38,9 +38,9 @@ namespace test {
 class ShelfTooltipManagerTest : public AshTestBase {
  public:
   ShelfTooltipManagerTest() {}
-  virtual ~ShelfTooltipManagerTest() {}
+  ~ShelfTooltipManagerTest() override {}
 
-  virtual void SetUp() override {
+  void SetUp() override {
     AshTestBase::SetUp();
     RootWindowController* controller = Shell::GetPrimaryRootWindowController();
     tooltip_manager_.reset(new ShelfTooltipManager(
@@ -48,7 +48,7 @@ class ShelfTooltipManagerTest : public AshTestBase {
         ShelfTestAPI(controller->shelf()->shelf()).shelf_view()));
   }
 
-  virtual void TearDown() override {
+  void TearDown() override {
     tooltip_manager_.reset();
     AshTestBase::TearDown();
   }