Fix mojo::shell::Context shutdown.

shell/child_process_host_unittest.cc

 // 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.
 
 // Note: This file also tests child_process.*.
 
 #include "shell/child_process_host.h"
 
 #include "base/logging.h"
 #include "base/macros.h"
@@ skipping 34 matching lines @@
       scoped_ptr<base::MessagePump>(new common::MessagePumpMojo()));
   context.Init();
   TestChildProcessHostDelegate child_process_host_delegate;
   ChildProcessHost child_process_host(&context, &child_process_host_delegate,
                                       ChildProcess::TYPE_TEST);
   child_process_host.Start();
   message_loop.Run();
   int exit_code = child_process_host.Join();
   VLOG(2) << "Joined child: exit_code = " << exit_code;
   EXPECT_EQ(0, exit_code);
+
+  context.Shutdown();
 }
 
 }  // namespace
 }  // namespace test
 }  // namespace shell
 }  // namespace mojo