Standardize usage of virtual/override/final specifiers.

ui/views/controls/message_box_view.h

Index: ui/views/controls/message_box_view.h
diff --git a/ui/views/controls/message_box_view.h b/ui/views/controls/message_box_view.h
index 912399559f460105be85bf8e801bf188ff66d853..120999a322a96c283fe58318c20a967eb00178f1 100644
--- a/ui/views/controls/message_box_view.h
+++ b/ui/views/controls/message_box_view.h
@@ -49,7 +49,7 @@ class VIEWS_EXPORT MessageBoxView : public View {
 
   explicit MessageBoxView(const InitParams& params);
 
-  virtual ~MessageBoxView();
+  ~MessageBoxView() override;
 
   // Returns the text box.
   views::Textfield* text_box() { return prompt_field_; }
@@ -74,14 +74,14 @@ class VIEWS_EXPORT MessageBoxView : public View {
   void SetLink(const base::string16& text, LinkListener* listener);
 
   // View:
-  virtual void GetAccessibleState(ui::AXViewState* state) override;
+  void GetAccessibleState(ui::AXViewState* state) override;
 
  protected:
   // View:
-  virtual void ViewHierarchyChanged(
+  void ViewHierarchyChanged(
       const ViewHierarchyChangedDetails& details) override;
   // Handles Ctrl-C and writes the message in the system clipboard.
-  virtual bool AcceleratorPressed(const ui::Accelerator& accelerator) override;
+  bool AcceleratorPressed(const ui::Accelerator& accelerator) override;
 
  private:
   // Sets up the layout manager and initializes the message labels and prompt