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

chrome/browser/safe_browsing/malware_details_cache.h

Index: chrome/browser/safe_browsing/malware_details_cache.h
diff --git a/chrome/browser/safe_browsing/malware_details_cache.h b/chrome/browser/safe_browsing/malware_details_cache.h
index a6b73979ee023325348e10835ccfd4503e00972d..ec855cf9c6419d1dbf82784301c856c607011305 100644
--- a/chrome/browser/safe_browsing/malware_details_cache.h
+++ b/chrome/browser/safe_browsing/malware_details_cache.h
@@ -54,12 +54,12 @@ class MalwareDetailsCacheCollector
  protected:
   // Implementation of URLFetcher::Delegate. Called after the request
   // completes (either successfully or with failure).
-  virtual void OnURLFetchComplete(const net::URLFetcher* source) override;
+  void OnURLFetchComplete(const net::URLFetcher* source) override;
 
  private:
   friend class base::RefCountedThreadSafe<MalwareDetailsCacheCollector>;
 
-  virtual ~MalwareDetailsCacheCollector();
+  ~MalwareDetailsCacheCollector() override;
 
   // Points to the url for which we are fetching the HTTP cache entry or
   // redirect chain.