Standardize usage of virtual/override/final specifiers.

ash/accelerators/accelerator_controller.h

Index: ash/accelerators/accelerator_controller.h
diff --git a/ash/accelerators/accelerator_controller.h b/ash/accelerators/accelerator_controller.h
index b0baa9c0d373931533bf221d8e0e860af0303cf9..9a7c579ac99df650045820ec1379b232fe3ebe41 100644
--- a/ash/accelerators/accelerator_controller.h
+++ b/ash/accelerators/accelerator_controller.h
@@ -36,7 +36,7 @@ class VolumeControlDelegate;
 class ASH_EXPORT AcceleratorController : public ui::AcceleratorTarget {
  public:
   AcceleratorController();
-  virtual ~AcceleratorController();
+  ~AcceleratorController() override;
 
   // A list of possible ways in which an accelerator should be restricted before
   // processing. Any target registered with this controller should respect
@@ -96,8 +96,8 @@ class ASH_EXPORT AcceleratorController : public ui::AcceleratorTarget {
   AcceleratorProcessingRestriction GetCurrentAcceleratorRestriction();
 
   // Overridden from ui::AcceleratorTarget:
-  virtual bool AcceleratorPressed(const ui::Accelerator& accelerator) override;
-  virtual bool CanHandleAccelerators() const override;
+  bool AcceleratorPressed(const ui::Accelerator& accelerator) override;
+  bool CanHandleAccelerators() const override;
 
   void SetBrightnessControlDelegate(
       scoped_ptr<BrightnessControlDelegate> brightness_control_delegate);