For the out-of-process NativeRunner, make sure that Start()'s callback always gets called.

shell/child_process_host.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 SHELL_CHILD_PROCESS_HOST_H_
 #define SHELL_CHILD_PROCESS_HOST_H_
 
 #include "base/macros.h"
 #include "base/process/process.h"
 #include "mojo/edk/embedder/platform_channel_pair.h"
 #include "mojo/edk/embedder/scoped_platform_handle.h"
-#include "shell/child_process.h"  // For |ChildProcess::Type|.
 
 namespace mojo {
 namespace shell {
 
 class Context;
 
 // (Base) class for a "child process host". Handles launching and connecting a
 // platform-specific "pipe" to the child, and supports joining the child
 // process.
 //
@@ skipping 41 matching lines @@
   // creation.
   embedder::ScopedPlatformHandle platform_channel_;
 
   DISALLOW_COPY_AND_ASSIGN(ChildProcessHost);
 };
 
 }  // namespace shell
 }  // namespace mojo
 
 #endif  // SHELL_CHILD_PROCESS_HOST_H_