Enforce marking "override" for functions overriding Blink in components/.

components/nacl/renderer/file_downloader.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <string>
 
 #include "base/callback.h"
 #include "base/files/file.h"
 #include "components/nacl/renderer/ppb_nacl_private.h"
 #include "third_party/WebKit/public/platform/WebURLLoaderClient.h"
@@ skipping 21 matching lines @@
 
   // Provides the bytes received so far, and the total bytes expected to be
   // received.
   typedef base::Callback<void(int64_t, int64_t)> ProgressCallback;
 
   FileDownloader(scoped_ptr<blink::WebURLLoader> url_loader,
                  base::File file,
                  StatusCallback status_cb,
                  ProgressCallback progress_cb);
 
-  virtual ~FileDownloader();
+  ~FileDownloader() override;
 
   void Load(const blink::WebURLRequest& request);
 
  private:
   // WebURLLoaderClient implementation.
-  virtual void didReceiveResponse(blink::WebURLLoader* loader,
-                                  const blink::WebURLResponse& response);
-  virtual void didReceiveData(blink::WebURLLoader* loader,
-                              const char* data,
-                              int data_length,
-                              int encoded_data_length);
-  virtual void didFinishLoading(blink::WebURLLoader* loader,
-                                double finish_time,
-                                int64_t total_encoded_data_length);
-  virtual void didFail(blink::WebURLLoader* loader,
-                       const blink::WebURLError& error);
+  void didReceiveResponse(blink::WebURLLoader* loader,
+                          const blink::WebURLResponse& response) override;
+  void didReceiveData(blink::WebURLLoader* loader,
+                      const char* data,
+                      int data_length,
+                      int encoded_data_length) override;
+  void didFinishLoading(blink::WebURLLoader* loader,
+                        double finish_time,
+                        int64_t total_encoded_data_length) override;
+  void didFail(blink::WebURLLoader* loader,
+               const blink::WebURLError& error) override;
 
   scoped_ptr<blink::WebURLLoader> url_loader_;
   base::File file_;
   StatusCallback status_cb_;
   ProgressCallback progress_cb_;
   int http_status_code_;
   int64_t total_bytes_received_;
   int64_t total_bytes_to_be_received_;
   Status status_;
 };
 
 }  // namespace nacl