Don't use IDENT_SRC_URL for HttpAuth challenges. IE hasn't supported it for years, and at worst ...

net/http/http_network_transaction_unittest.cc

 // Copyright (c) 2012 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.
 
 #include "net/http/http_network_transaction.h"
 
 #include <math.h>  // ceil
 #include <stdarg.h>
 #include <string>
 #include <vector>
@@ skipping 4245 matching lines @@
   request.url = GURL("http://foo:b@r@www.google.com/");
 
   SessionDependencies session_deps;
   scoped_ptr<HttpTransaction> trans(
       new HttpNetworkTransaction(CreateSession(&session_deps)));
 
   // The password contains an escaped character -- for this test to pass it
   // will need to be unescaped by HttpNetworkTransaction.
   EXPECT_EQ("b%40r", request.url.password());
 
-  request.load_flags = LOAD_NORMAL;
+  request.load_flags = LOAD_NORMAL | LOAD_ENABLE_EMBEDDED_IDENTITY;
 
   MockWrite data_writes1[] = {
     MockWrite("GET / HTTP/1.1\r\n"
               "Host: www.google.com\r\n"
               "Connection: keep-alive\r\n\r\n"),
   };
 
   MockRead data_reads1[] = {
     MockRead("HTTP/1.0 401 Unauthorized\r\n"),
     MockRead("WWW-Authenticate: Basic realm=\"MyRealm1\"\r\n"),
@@ skipping 53 matching lines @@
 
 // Test the request-challenge-retry sequence for basic auth when there is
 // an incorrect identity in the URL. The identity from the URL should be used
 // only once.
 TEST_F(HttpNetworkTransactionTest, WrongAuthIdentityInURL) {
   HttpRequestInfo request;
   request.method = "GET";
   // Note: the URL has a username:password in it.  The password "baz" is
   // wrong (should be "bar").
   request.url = GURL("http://foo:baz@www.google.com/");
-
-  request.load_flags = LOAD_NORMAL;
+  request.load_flags = LOAD_NORMAL | LOAD_ENABLE_EMBEDDED_IDENTITY;
 
   SessionDependencies session_deps;
   scoped_ptr<HttpTransaction> trans(
       new HttpNetworkTransaction(CreateSession(&session_deps)));
 
   MockWrite data_writes1[] = {
     MockWrite("GET / HTTP/1.1\r\n"
               "Host: www.google.com\r\n"
               "Connection: keep-alive\r\n\r\n"),
   };
@@ skipping 5576 matching lines @@
   StaticSocketDataProvider* data[] = { &data1, &data2 };
 
   SimpleGetHelperResult out = SimpleGetHelperForData(data, arraysize(data));
 
   EXPECT_EQ(OK, out.rv);
   EXPECT_EQ("HTTP/1.0 200 OK", out.status_line);
   EXPECT_EQ("hello world", out.response_data);
 }
 
 }  // namespace net