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

net/http/http_auth_handler_mock.h

Index: net/http/http_auth_handler_mock.h
diff --git a/net/http/http_auth_handler_mock.h b/net/http/http_auth_handler_mock.h
index f9a676c4f3bd4ba521382e7602f0fb7e1d632765..a6b0d488de3a77d9f03fb93da03d60400cb9f838 100644
--- a/net/http/http_auth_handler_mock.h
+++ b/net/http/http_auth_handler_mock.h
@@ -10,6 +10,7 @@
 
 #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"
 
@@ -46,15 +47,23 @@ class HttpAuthHandlerMock : public HttpAuthHandler {
     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,
@@ -65,6 +74,7 @@ class HttpAuthHandlerMock : public HttpAuthHandler {
 
    private:
     scoped_ptr<HttpAuthHandler> handlers_[HttpAuth::AUTH_NUM_TARGETS];
+    bool do_init_from_challenge_;
   };
 
  protected:
@@ -89,6 +99,7 @@ class HttpAuthHandlerMock : public HttpAuthHandler {
   std::string* auth_token_;
   bool first_round_;
   bool connection_based_;
+  GURL request_url_;
 };
 
 }  // namespace net