Remove the implicit fallback to DIRECT when proxies fail. This better matches...

net/http/http_network_transaction_unittest.cc

 // Copyright (c) 2009 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 <math.h>  // ceil
 
 #include "base/compiler_specific.h"
 #include "net/base/completion_callback.h"
 #include "net/base/mock_host_resolver.h"
 #include "net/base/request_priority.h"
@@ skipping 3538 matching lines @@
     EXPECT_EQ(ERR_IO_PENDING, trans->Start(&request, &callback, NULL));
     EXPECT_EQ(tests[i].expected_group_name,
               conn_pool->last_group_name_received());
   }
 }
 
 TEST_F(HttpNetworkTransactionTest, ReconsiderProxyAfterFailedConnection) {
   SessionDependencies session_deps(
       CreateFixedProxyService("myproxy:70;foobar:80"));
 
+  // This simulates failure resolving all hostnames; that means we will fail
+  // connecting to both proxies (myproxy:70 and foobar:80).
   session_deps.host_resolver->rules()->AddSimulatedFailure("*");
 
   scoped_ptr<HttpTransaction> trans(
       new HttpNetworkTransaction(CreateSession(&session_deps)));
 
   HttpRequestInfo request;
   request.method = "GET";
   request.url = GURL("http://www.google.com/");
 
   TestCompletionCallback callback;
@@ skipping 328 matching lines @@
     MockRead("HTTP/1.0 200 OK\r\nContent-Length:6719476739\r\n\r\n"),
     MockRead(false, OK),
   };
   SimpleGetHelperResult out = SimpleGetHelper(data_reads);
   EXPECT_EQ(OK, out.rv);
   EXPECT_EQ("HTTP/1.0 200 OK", out.status_line);
   EXPECT_EQ("", out.response_data);
 }
 
 }  // namespace net