Standardize usage of virtual/override/final in chrome/browser/ui/

chrome/browser/ui/cocoa/extensions/browser_action_button.mm

Index: chrome/browser/ui/cocoa/extensions/browser_action_button.mm
diff --git a/chrome/browser/ui/cocoa/extensions/browser_action_button.mm b/chrome/browser/ui/cocoa/extensions/browser_action_button.mm
index 61af4e7c13070bb9b1cfb567defdb6bcf64c342c..fec50ea7952442e11ed36749108dc4f7678fe406 100644
--- a/chrome/browser/ui/cocoa/extensions/browser_action_button.mm
+++ b/chrome/browser/ui/cocoa/extensions/browser_action_button.mm
@@ -49,12 +49,10 @@ class ExtensionActionIconFactoryBridge
         icon_factory_(profile, extension, browser_action_, this) {
   }
 
-  virtual ~ExtensionActionIconFactoryBridge() {}
+  ~ExtensionActionIconFactoryBridge() override {}
 
   // ExtensionActionIconFactory::Observer implementation.
-  virtual void OnIconUpdated() override {
-    [owner_ updateState];
-  }
+  void OnIconUpdated() override { [owner_ updateState]; }
 
   gfx::Image GetIcon(int tabId) {
     return icon_factory_.GetIcon(tabId);