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

components/nacl/renderer/manifest_downloader.h

Index: components/nacl/renderer/manifest_downloader.h
diff --git a/components/nacl/renderer/manifest_downloader.h b/components/nacl/renderer/manifest_downloader.h
index 0e36203bc92836d5c283a3c4803e1ece2f7dbbde..b82ad31b8a35ef5d2b67e8305914b075841c16cb 100644
--- a/components/nacl/renderer/manifest_downloader.h
+++ b/components/nacl/renderer/manifest_downloader.h
@@ -32,7 +32,7 @@ class ManifestDownloader : public blink::WebURLLoaderClient {
   ManifestDownloader(scoped_ptr<blink::WebURLLoader> url_loader,
                      bool is_installed,
                      Callback cb);
-  virtual ~ManifestDownloader();
+  ~ManifestDownloader() override;
 
   void Load(const blink::WebURLRequest& request);
 
@@ -40,17 +40,17 @@ class ManifestDownloader : public blink::WebURLLoaderClient {
   void Close();
 
   // 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_;
   bool is_installed_;