make content_shell and content_browsertests works with aura

content/shell/shell_browser_main_parts.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_browser_main_parts.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/message_loop.h"
 #include "base/string_number_conversions.h"
@@ skipping 86 matching lines @@
     delete parameters_.ui_task;
     run_message_loop_ = false;
   }
 }
 
 bool ShellBrowserMainParts::MainMessageLoopRun(int* result_code)  {
   return !run_message_loop_;
 }
 
 void ShellBrowserMainParts::PostMainMessageLoopRun() {
+#if defined(USE_AURA)
+  Shell::PlatformExit();
+#endif
   if (devtools_delegate_)
     devtools_delegate_->Stop();
   browser_context_.reset();
 }
 
 }  // namespace