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

chrome/browser/history/chrome_history_client_factory.h

Index: chrome/browser/history/chrome_history_client_factory.h
diff --git a/chrome/browser/history/chrome_history_client_factory.h b/chrome/browser/history/chrome_history_client_factory.h
index 01eb7f479890c9cfe7b2fe19c5a70b55abe84320..9b8a32f9863c9fc34f7aae063259aaa31c9b38c6 100644
--- a/chrome/browser/history/chrome_history_client_factory.h
+++ b/chrome/browser/history/chrome_history_client_factory.h
@@ -30,14 +30,14 @@ class ChromeHistoryClientFactory : public BrowserContextKeyedServiceFactory {
   friend struct DefaultSingletonTraits<ChromeHistoryClientFactory>;
 
   ChromeHistoryClientFactory();
-  virtual ~ChromeHistoryClientFactory();
+  ~ChromeHistoryClientFactory() override;
 
   // BrowserContextKeyedServiceFactory:
-  virtual KeyedService* BuildServiceInstanceFor(
+  KeyedService* BuildServiceInstanceFor(
       content::BrowserContext* context) const override;
-  virtual content::BrowserContext* GetBrowserContextToUse(
+  content::BrowserContext* GetBrowserContextToUse(
       content::BrowserContext* context) const override;
-  virtual bool ServiceIsNULLWhileTesting() const override;
+  bool ServiceIsNULLWhileTesting() const override;
 };
 
 #endif  // CHROME_BROWSER_HISTORY_CHROME_HISTORY_CLIENT_FACTORY_H_