Add the "virtual" keyword on method overrides that are missing it.

chrome/browser/renderer_host/safe_browsing_resource_handler.h

Index: chrome/browser/renderer_host/safe_browsing_resource_handler.h
diff --git a/chrome/browser/renderer_host/safe_browsing_resource_handler.h b/chrome/browser/renderer_host/safe_browsing_resource_handler.h
index 14ddd4ba8630e16fcb77e92b0f4afc4bf4261662..13869354061af22f6e41b2a52f29d459d183c578 100644
--- a/chrome/browser/renderer_host/safe_browsing_resource_handler.h
+++ b/chrome/browser/renderer_host/safe_browsing_resource_handler.h
@@ -52,32 +52,32 @@ class SafeBrowsingResourceHandler : public ResourceHandler,
                               ResourceDispatcherHost::Receiver* receiver);
 
   // ResourceHandler implementation:
-  bool OnUploadProgress(int request_id, uint64 position, uint64 size);
-  bool OnRequestRedirected(int request_id, const GURL& new_url,
-                           ResourceResponse* response, bool* defer);
-  bool OnResponseStarted(int request_id, ResourceResponse* response);
-  bool OnWillStart(int request_id, const GURL& url, bool* defer);
-  bool OnWillRead(int request_id, net::IOBuffer** buf, int* buf_size,
-                  int min_size);
-  bool OnReadCompleted(int request_id, int* bytes_read);
-  bool OnResponseCompleted(int request_id,
-                           const URLRequestStatus& status,
-                           const std::string& security_info);
+  virtual bool OnUploadProgress(int request_id, uint64 position, uint64 size);
+  virtual bool OnRequestRedirected(int request_id, const GURL& new_url,
+                                   ResourceResponse* response, bool* defer);
+  virtual bool OnResponseStarted(int request_id, ResourceResponse* response);
+  virtual bool OnWillStart(int request_id, const GURL& url, bool* defer);
+  virtual bool OnWillRead(int request_id, net::IOBuffer** buf, int* buf_size,
+                          int min_size);
+  virtual bool OnReadCompleted(int request_id, int* bytes_read);
+  virtual bool OnResponseCompleted(int request_id,
+                                   const URLRequestStatus& status,
+                                   const std::string& security_info);
   virtual void OnRequestClosed();
 
   // SafeBrowsingService::Client implementation, called on the IO thread once
   // the URL has been classified.
-  void OnUrlCheckResult(const GURL& url,
-                        SafeBrowsingService::UrlCheckResult result);
+  virtual void OnUrlCheckResult(const GURL& url,
+                                SafeBrowsingService::UrlCheckResult result);
 
   // SafeBrowsingService::Client implementation, called on the IO thread when
   // the user has decided to proceed with the current request, or go back.
-  void OnBlockingPageComplete(bool proceed);
+  virtual void OnBlockingPageComplete(bool proceed);
 
   // NotificationObserver interface.
-  void Observe(NotificationType type,
-               const NotificationSource& source,
-               const NotificationDetails& details);
+  virtual void Observe(NotificationType type,
+                       const NotificationSource& source,
+                       const NotificationDetails& details);
 
  private:
   // Describes what phase of the check a handler is in.