Update {virtual,override} to follow C++11 style in components.

components/renderer_context_menu/render_view_context_menu_observer.h

Index: components/renderer_context_menu/render_view_context_menu_observer.h
diff --git a/components/renderer_context_menu/render_view_context_menu_observer.h b/components/renderer_context_menu/render_view_context_menu_observer.h
index 3ae47d9fae1d73f231c454781c434a7ee9b99a57..586f978663a90c01d330ecdc1cf6b8802fab8d08 100644
--- a/components/renderer_context_menu/render_view_context_menu_observer.h
+++ b/components/renderer_context_menu/render_view_context_menu_observer.h
@@ -30,12 +30,12 @@ struct ContextMenuParams;
 //  class MyMenuObserver : public RenderViewContextMenuObserver {
 //   public:
 //    MyMenuObserver(RenderViewContextMenuProxy* p);
-//    ~MyMenuObserver();
+//    ~MyMenuObserver() override;
 //
-//    virtual void InitMenu(const content::ContextMenuParams& params) override;
-//    virtual bool IsCommandIdSupported(int command_id) override;
-//    virtual bool IsCommandIdEnabled(int command_id) override;
-//    virtual void ExecuteCommand(int command_id) override;
+//    void InitMenu(const content::ContextMenuParams& params) override;
+//    bool IsCommandIdSupported(int command_id) override;
+//    bool IsCommandIdEnabled(int command_id) override;
+//    void ExecuteCommand(int command_id) override;
 //
 //   private:
 //    RenderViewContextMenuProxy* proxy_;