C++11 override style change for athena

athena/test/base/sample_activity_factory.h

Index: athena/test/base/sample_activity_factory.h
diff --git a/athena/test/base/sample_activity_factory.h b/athena/test/base/sample_activity_factory.h
index 7eef19b7e64f8a885f98e8e0924582ef9af17b35..83b057ad1018502d5ef87c629b229da35b392a4d 100644
--- a/athena/test/base/sample_activity_factory.h
+++ b/athena/test/base/sample_activity_factory.h
@@ -14,14 +14,14 @@ namespace test {
 class SampleActivityFactory : public ActivityFactory {
  public:
   SampleActivityFactory();
-  virtual ~SampleActivityFactory();
+  ~SampleActivityFactory() override;
 
   // Overridden from ActivityFactory:
-  virtual Activity* CreateWebActivity(content::BrowserContext* browser_context,
+  Activity* CreateWebActivity(content::BrowserContext* browser_context,
                                       const base::string16& title,
                                       const GURL& url) override;
-  virtual Activity* CreateWebActivity(content::WebContents* contents) override;
-  virtual Activity* CreateAppActivity(const std::string& app_id,
+  Activity* CreateWebActivity(content::WebContents* contents) override;
+  Activity* CreateAppActivity(const std::string& app_id,
                                       views::WebView* web_view) override;
 
  private: