Use SSPI for NTLM authentication on Windows....

net/http/http_auth_handler.h

 // Copyright (c) 2006-2008 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_H_
 #define NET_HTTP_HTTP_AUTH_HANDLER_H_
 
 #include <string>
 
 #include "base/ref_counted.h"
@@ skipping 50 matching lines @@
   bool is_connection_based() const {
     return (properties_ & IS_CONNECTION_BASED) != 0;
   }
 
   // Returns true if the response to the current authentication challenge
   // requires an identity.
   // TODO(wtc): Find a better way to handle a multi-round challenge-response
   // sequence used by a connection-based authentication scheme.
   virtual bool NeedsIdentity() { return true; }
 
+  // Returns true if this is the final round of the authentication sequence.
+  // For Basic and Digest, the method always returns true because they are
+  // single-round schemes.
+  virtual bool IsFinalRound() { return true; }
+
   // Generate the Authorization header value.
   virtual std::string GenerateCredentials(const std::wstring& username,
                                           const std::wstring& password,
                                           const HttpRequestInfo* request,
                                           const ProxyInfo* proxy) = 0;
 
  protected:
   enum Property {
     ENCRYPTS_IDENTITY = 1 << 0,
     IS_CONNECTION_BASED = 1 << 1,
@@ skipping 18 matching lines @@
   // origin server.
   HttpAuth::Target target_;
 
   // A bitmask of the properties of the authentication scheme.
   int properties_;
 };
 
 }  // namespace net
 
 #endif  // NET_HTTP_HTTP_AUTH_HANDLER_H_