Standardize usage of virtual/override/final specifiers.

ash/test/test_volume_control_delegate.h

Index: ash/test/test_volume_control_delegate.h
diff --git a/ash/test/test_volume_control_delegate.h b/ash/test/test_volume_control_delegate.h
index 751e04efe28808a833119a9f27c920830a789858..009ce6641455bb49e9affbc8eaaf3b1ae5d6419b 100644
--- a/ash/test/test_volume_control_delegate.h
+++ b/ash/test/test_volume_control_delegate.h
@@ -16,7 +16,7 @@ namespace ash {
 class TestVolumeControlDelegate : public ash::VolumeControlDelegate {
  public:
   explicit TestVolumeControlDelegate(bool consume);
-  virtual ~TestVolumeControlDelegate();
+  ~TestVolumeControlDelegate() override;
 
   int handle_volume_mute_count() const {
     return handle_volume_mute_count_;
@@ -35,9 +35,9 @@ class TestVolumeControlDelegate : public ash::VolumeControlDelegate {
   }
 
   // ash::VolumeControlDelegate:
-  virtual bool HandleVolumeMute(const ui::Accelerator& accelerator) override;
-  virtual bool HandleVolumeDown(const ui::Accelerator& accelerator) override;
-  virtual bool HandleVolumeUp(const ui::Accelerator& accelerator) override;
+  bool HandleVolumeMute(const ui::Accelerator& accelerator) override;
+  bool HandleVolumeDown(const ui::Accelerator& accelerator) override;
+  bool HandleVolumeUp(const ui::Accelerator& accelerator) override;
 
  private:
   // Keeps track of the return value that should be used for the methods