Fix TaskScheduler initialization in remoting processes.

remoting/host/setup/me2me_native_messaging_host_main.cc

 // Copyright 2013 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 "remoting/host/setup/me2me_native_messaging_host_main.h"
 
 #include <cstdint>
 #include <memory>
 #include <string>
 #include <utility>
@@ skipping 251 matching lines @@
                                    static_cast<intptr_t>(native_view_handle),
                                    std::move(context), daemon_controller,
                                    pairing_registry, std::move(oauth_client)));
 
   host->Start(native_messaging_pipe.get());
 
   native_messaging_pipe->Start(std::move(host), std::move(channel));
 
   // Run the loop until channel is alive.
   run_loop.Run();
+
+  // Block until tasks blocking shutdown have completed their execution.
+  base::TaskScheduler::GetInstance()->Shutdown();
+
   return kSuccessExitCode;
 }
 
 }  // namespace remoting