replace OVERRIDE and FINAL with override and final in ash/

ash/shell/window_watcher.cc

Index: ash/shell/window_watcher.cc
diff --git a/ash/shell/window_watcher.cc b/ash/shell/window_watcher.cc
index d7bc72683c307b2c46bcf19e2f0673f81e4b6bc3..f56cf78983eb7f11324f26c3e3ceeae8f495ad40 100644
--- a/ash/shell/window_watcher.cc
+++ b/ash/shell/window_watcher.cc
@@ -28,11 +28,11 @@ class WindowWatcher::WorkspaceWindowWatcher : public aura::WindowObserver {
   virtual ~WorkspaceWindowWatcher() {
   }
 
-  virtual void OnWindowAdded(aura::Window* new_window) OVERRIDE {
+  virtual void OnWindowAdded(aura::Window* new_window) override {
     new_window->AddObserver(watcher_);
   }
 
-  virtual void OnWillRemoveWindow(aura::Window* window) OVERRIDE {
+  virtual void OnWillRemoveWindow(aura::Window* window) override {
     DCHECK(window->children().empty());
     window->RemoveObserver(watcher_);
   }