Alternate-Protocol was failing when going through Digest authenticating proxy.

net/http/http_auth_handler_mock.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_MOCK_H_
 #define NET_HTTP_HTTP_AUTH_HANDLER_MOCK_H_
 #pragma once
 
 #include <string>
 
 #include "base/string16.h"
 #include "base/task.h"
+#include "googleurl/src/gurl.h"
 #include "net/http/http_auth_handler.h"
 #include "net/http/http_auth_handler_factory.h"
 
 namespace net {
 
 // MockAuthHandler is used in tests to reliably trigger edge cases.
 class HttpAuthHandlerMock : public HttpAuthHandler {
  public:
   enum Resolve {
     RESOLVE_INIT,
@@ skipping 16 matching lines @@
 
   virtual bool NeedsIdentity() { return first_round_; }
   virtual bool IsFinalRound() { return false; }
 
   void SetGenerateExpectation(bool async, int rv);
 
   void set_connection_based(bool connection_based) {
     connection_based_ = connection_based;
   }
 
+  const GURL& request_url() const {
+    return request_url_;
+  }
+
   // The Factory class simply returns the same handler each time
   // CreateAuthHandler is called.
   class Factory : public HttpAuthHandlerFactory {
    public:
-    Factory() {}
-    virtual ~Factory() {}
+    Factory();
+    virtual ~Factory();
 
     void set_mock_handler(HttpAuthHandler* handler, HttpAuth::Target target);
 
+    void set_do_init_from_challenge(bool do_init_from_challenge) {
+      do_init_from_challenge_ = do_init_from_challenge;
+    }
+
     virtual int CreateAuthHandler(HttpAuth::ChallengeTokenizer* challenge,
                                   HttpAuth::Target target,
                                   const GURL& origin,
                                   CreateReason reason,
                                   int nonce_count,
                                   const BoundNetLog& net_log,
                                   scoped_ptr<HttpAuthHandler>* handler);
 
    private:
     scoped_ptr<HttpAuthHandler> handlers_[HttpAuth::AUTH_NUM_TARGETS];
+    bool do_init_from_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:
   void OnResolveCanonicalName();
 
   void OnGenerateAuthToken();
 
   Resolve resolve_;
   CompletionCallback* user_callback_;
   ScopedRunnableMethodFactory<HttpAuthHandlerMock> method_factory_;
   bool generate_async_;
   int generate_rv_;
   std::string* auth_token_;
   bool first_round_;
   bool connection_based_;
+  GURL request_url_;
 };
 
 }  // namespace net
 
 #endif  // NET_HTTP_HTTP_AUTH_HANDLER_MOCK_H_