webRequest.onAuthRequired listeners can provide authentication credentials.

chrome/browser/net/chrome_network_delegate.h

 // Copyright (c) 2011 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 CHROME_BROWSER_NET_CHROME_NETWORK_DELEGATE_H_
 #define CHROME_BROWSER_NET_CHROME_NETWORK_DELEGATE_H_
 #pragma once
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
@@ skipping 45 matching lines @@
                              const net::HttpRequestHeaders& headers) OVERRIDE;
   virtual void OnBeforeRedirect(net::URLRequest* request,
                                 const GURL& new_location) OVERRIDE;
   virtual void OnResponseStarted(net::URLRequest* request) OVERRIDE;
   virtual void OnRawBytesRead(const net::URLRequest& request,
                               int bytes_read) OVERRIDE;
   virtual void OnCompleted(net::URLRequest* request) OVERRIDE;
   virtual void OnURLRequestDestroyed(net::URLRequest* request) OVERRIDE;
   virtual void OnPACScriptError(int line_number,
                                 const string16& error) OVERRIDE;
-  virtual void OnAuthRequired(net::URLRequest* request,
-                              const net::AuthChallengeInfo& auth_info) OVERRIDE;
+  virtual int OnAuthRequired(net::URLRequest* request,
+                             const net::AuthChallengeInfo& auth_info,
+                             net::CompletionCallback* callback,
+                             net::AuthCredentials* credentials) OVERRIDE;
 
   scoped_refptr<ExtensionEventRouterForwarder> event_router_;
   void* profile_;
 
   scoped_refptr<ExtensionInfoMap> extension_info_map_;
 
   // Weak, owned by our owner.
   BooleanPrefMember* enable_referrers_;
 
   // Weak, owned by our owner.
   const policy::URLBlacklistManager* url_blacklist_manager_;
 
   DISALLOW_COPY_AND_ASSIGN(ChromeNetworkDelegate);
 };
 
 #endif  // CHROME_BROWSER_NET_CHROME_NETWORK_DELEGATE_H_