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

net/http/http_auth_handler_basic.h

 // Copyright (c) 2010 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.
 
 #ifndef NET_HTTP_HTTP_AUTH_HANDLER_BASIC_H_
 #define NET_HTTP_HTTP_AUTH_HANDLER_BASIC_H_
 #pragma once
 
 #include <string>
 
@@ skipping 13 matching lines @@
 
     virtual int CreateAuthHandler(HttpAuth::ChallengeTokenizer* challenge,
                                   HttpAuth::Target target,
                                   const GURL& origin,
                                   CreateReason reason,
                                   int digest_nonce_count,
                                   const BoundNetLog& net_log,
                                   scoped_ptr<HttpAuthHandler>* handler);
   };
 
-  HttpAuth::AuthorizationResult HandleAnotherChallenge(
+  virtual HttpAuth::AuthorizationResult HandleAnotherChallenge(
       HttpAuth::ChallengeTokenizer* challenge);
 
  protected:
   virtual bool Init(HttpAuth::ChallengeTokenizer* challenge);
 
   virtual int GenerateAuthTokenImpl(const string16* username,
                                     const string16* password,
                                     const HttpRequestInfo* request,
                                     CompletionCallback* callback,
                                     std::string* auth_token);
 
  private:
   ~HttpAuthHandlerBasic() {}
 
   bool ParseChallenge(HttpAuth::ChallengeTokenizer* challenge);
 };
 
 }  // namespace net
 
 #endif  // NET_HTTP_HTTP_AUTH_HANDLER_BASIC_H_