Fixing a Dr. memory failure in the remoting unit tests.

remoting/host/security_key/remote_security_key_message_reader_impl.cc

 // Copyright 2016 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/security_key/remote_security_key_message_reader_impl.h"
 
 #include <cstdint>
 #include <string>
 #include <utility>
 
@@ skipping 16 matching lines @@
   options.message_loop_type = base::MessageLoop::TYPE_IO;
   reader_thread_.StartWithOptions(options);
 
   read_task_runner_ = reader_thread_.task_runner();
   main_task_runner_ = base::ThreadTaskRunnerHandle::Get();
 }
 
 RemoteSecurityKeyMessageReaderImpl::~RemoteSecurityKeyMessageReaderImpl() {
   DCHECK(main_task_runner_->RunsTasksOnCurrentThread());
 
-  // In order to ensure the reader thread is stopped cleanly, we close the
-  // stream it is blocking on and then wait for the thread to exit.
-  read_stream_.Close();
+  // In order to ensure the reader thread is stopped cleanly, we want to stop
+  // the thread before the task runners and weak pointers are invalidated.
   reader_thread_.Stop();
 }
 
 void RemoteSecurityKeyMessageReaderImpl::Start(
     const SecurityKeyMessageCallback& message_callback,
     const base::Closure& error_callback) {
   DCHECK(main_task_runner_->RunsTasksOnCurrentThread());
 
   message_callback_ = message_callback;
   error_callback_ = error_callback;
@@ skipping 75 matching lines @@
   DCHECK(main_task_runner_->RunsTasksOnCurrentThread());
   message_callback_.Run(std::move(message));
 }
 
 void RemoteSecurityKeyMessageReaderImpl::InvokeErrorCallback() {
   DCHECK(main_task_runner_->RunsTasksOnCurrentThread());
   error_callback_.Run();
 }
 
 }  // namespace remoting