[content shell] disable the auth prompt during layout tests

content/shell/shell_resource_dispatcher_host_delegate.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 "content/shell/shell_resource_dispatcher_host_delegate.h"
 
+#include "base/command_line.h"
 #include "content/shell/shell_login_dialog.h"
+#include "content/shell/shell_switches.h"
 
 namespace content {
 
 ShellResourceDispatcherHostDelegate::ShellResourceDispatcherHostDelegate() {
 }
 
 ShellResourceDispatcherHostDelegate::~ShellResourceDispatcherHostDelegate() {
 }
 
 bool ShellResourceDispatcherHostDelegate::AcceptAuthRequest(
     net::URLRequest* request,
     net::AuthChallengeInfo* auth_info) {
-  // Why not give it a try?
-  return true;
+  bool accept_auth_request =
+      !CommandLine::ForCurrentProcess()->HasSwitch(switches::kDumpRenderTree);
+  return accept_auth_request;
 }
 
 ResourceDispatcherHostLoginDelegate*
 ShellResourceDispatcherHostDelegate::CreateLoginDelegate(
     net::AuthChallengeInfo* auth_info, net::URLRequest* request) {
   if (!login_request_callback_.is_null()) {
     login_request_callback_.Run();
     login_request_callback_.Reset();
     return NULL;
   }
 
 #if !defined(OS_MACOSX) && !defined(TOOLKIT_GTK)
 // TODO: implement ShellLoginDialog for other platforms, drop this #if
   return NULL;
 #else
   return new ShellLoginDialog(auth_info, request);
 #endif
 }
 
 }  // namespace content