Standardize usage of virtual/override/final in components/

components/gcm_driver/gcm_channel_status_request.h

Index: components/gcm_driver/gcm_channel_status_request.h
diff --git a/components/gcm_driver/gcm_channel_status_request.h b/components/gcm_driver/gcm_channel_status_request.h
index e1ddf159d9f736ab5de2679b5bf2c26280b5d0de..1be074f18a6d8b94df3dca26184004829f204894 100644
--- a/components/gcm_driver/gcm_channel_status_request.h
+++ b/components/gcm_driver/gcm_channel_status_request.h
@@ -42,7 +42,7 @@ class GCMChannelStatusRequest : public net::URLFetcherDelegate {
       const std::string& channel_status_request_url,
       const std::string& user_agent,
       const GCMChannelStatusRequestCallback& callback);
-  virtual ~GCMChannelStatusRequest();
+  ~GCMChannelStatusRequest() override;
 
   void Start();
 
@@ -53,7 +53,7 @@ class GCMChannelStatusRequest : public net::URLFetcherDelegate {
   FRIEND_TEST_ALL_PREFIXES(GCMChannelStatusRequestTest, RequestData);
 
   // Overridden from URLFetcherDelegate:
-  virtual void OnURLFetchComplete(const net::URLFetcher* source) override;
+  void OnURLFetchComplete(const net::URLFetcher* source) override;
 
   bool ParseResponse(const net::URLFetcher* source);
   void RetryWithBackoff(bool update_backoff);