Standardize usage of virtual/override/final in sync/

sync/test/accounts_client/url_request_context_getter.h

Index: sync/test/accounts_client/url_request_context_getter.h
diff --git a/sync/test/accounts_client/url_request_context_getter.h b/sync/test/accounts_client/url_request_context_getter.h
index aecf658d8581a0b6f8d14fa8556f6b2dc0bfe87f..20a39310b722dfade2da57a6ec761aafcc1ef2ca 100644
--- a/sync/test/accounts_client/url_request_context_getter.h
+++ b/sync/test/accounts_client/url_request_context_getter.h
@@ -25,12 +25,12 @@ class URLRequestContextGetter : public net::URLRequestContextGetter {
       scoped_refptr<base::SingleThreadTaskRunner> network_task_runner);
 
   // Overridden from net::URLRequestContextGetter:
-  virtual net::URLRequestContext* GetURLRequestContext() override;
-  virtual scoped_refptr<base::SingleThreadTaskRunner>
-      GetNetworkTaskRunner() const override;
+  net::URLRequestContext* GetURLRequestContext() override;
+  scoped_refptr<base::SingleThreadTaskRunner> GetNetworkTaskRunner()
+      const override;
 
  private:
-  virtual ~URLRequestContextGetter();
+  ~URLRequestContextGetter() override;
 
   scoped_refptr<base::SingleThreadTaskRunner> network_task_runner_;