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

chrome/browser/speech/extension_api/tts_engine_extension_observer.cc

Index: chrome/browser/speech/extension_api/tts_engine_extension_observer.cc
diff --git a/chrome/browser/speech/extension_api/tts_engine_extension_observer.cc b/chrome/browser/speech/extension_api/tts_engine_extension_observer.cc
index c760a484ffb5c3331c6bc4a322faab6a91e089d4..6ea032db3204d6cca9ab1a0a9de9734e870fb8ac 100644
--- a/chrome/browser/speech/extension_api/tts_engine_extension_observer.cc
+++ b/chrome/browser/speech/extension_api/tts_engine_extension_observer.cc
@@ -42,16 +42,16 @@ class TtsEngineExtensionObserverFactory
     DependsOn(extensions::ExtensionSystemFactory::GetInstance());
   }
 
-  virtual ~TtsEngineExtensionObserverFactory() {}
+  ~TtsEngineExtensionObserverFactory() override {}
 
-  virtual content::BrowserContext* GetBrowserContextToUse(
+  content::BrowserContext* GetBrowserContextToUse(
       content::BrowserContext* context) const override {
     // If given an incognito profile (including the Chrome OS login
     // profile), share the service with the original profile.
     return chrome::GetBrowserContextRedirectedInIncognito(context);
   }
 
-  virtual KeyedService* BuildServiceInstanceFor(
+  KeyedService* BuildServiceInstanceFor(
       content::BrowserContext* profile) const override {
     return new TtsEngineExtensionObserver(static_cast<Profile*>(profile));
   }