C++11 override style change for athena

athena/virtual_keyboard/virtual_keyboard_manager_impl.cc

Index: athena/virtual_keyboard/virtual_keyboard_manager_impl.cc
diff --git a/athena/virtual_keyboard/virtual_keyboard_manager_impl.cc b/athena/virtual_keyboard/virtual_keyboard_manager_impl.cc
index 4c19e2ace7f00b56ddaebb504d38e3b9d1648bbd..7acca11f4980eeaebda15d14b182de3b9641b25d 100644
--- a/athena/virtual_keyboard/virtual_keyboard_manager_impl.cc
+++ b/athena/virtual_keyboard/virtual_keyboard_manager_impl.cc
@@ -32,7 +32,7 @@ class BasicKeyboardControllerProxy : public keyboard::KeyboardControllerProxy {
   BasicKeyboardControllerProxy(content::BrowserContext* context,
                                aura::Window* root_window)
       : browser_context_(context), root_window_(root_window) {}
-  virtual ~BasicKeyboardControllerProxy() {}
+  ~BasicKeyboardControllerProxy() override {}
 
   // keyboard::KeyboardControllerProxy:
   virtual ui::InputMethod* GetInputMethod() override {
@@ -68,7 +68,7 @@ class VirtualKeyboardManagerImpl : public VirtualKeyboardManager {
     Init();
   }
 
-  virtual ~VirtualKeyboardManagerImpl() {
+  ~VirtualKeyboardManagerImpl() override {
     CHECK_EQ(this, instance);
     instance = nullptr;