mojo: shell::Context should outlive the shell MessageLoop

mojo/shell/shell_test_helper.h

 // Copyright 2014 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.
 
 #ifndef MOJO_SHELL_SHELL_TEST_HELPER_
 #define MOJO_SHELL_SHELL_TEST_HELPER_
 
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/run_loop.h"
@@ skipping 22 matching lines @@
   // Returns a handle to the ServiceManager. ShellTestHelper owns the
   // ServiceProvider.
   ServiceManager* service_manager() { return context_->service_manager(); }
 
   // Sets a ServiceLoader for the specified URL. |loader| is ultimately used on
   // the thread this class spawns.
   void SetLoaderForURL(scoped_ptr<ServiceLoader> loader, const GURL& url);
 
  private:
   scoped_ptr<Context> context_;
+  base::MessageLoop shell_loop_;
   scoped_ptr<ServiceManager::TestAPI> test_api_;
   DISALLOW_COPY_AND_ASSIGN(ShellTestHelper);
 };
 
 }  // namespace shell
 }  // namespace mojo
 
 #endif  // MOJO_SHELL_SHELL_TEST_HELPER_