Fix race in EmbeddedApplicationRunner::ShutDown

content/common/mojo/embedded_application_runner.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 "content/common/mojo/embedded_application_runner.h"
 
 #include <vector>
 
 #include "base/bind.h"
 #include "base/macros.h"
@@ skipping 35 matching lines @@
     DCHECK(application_task_runner_);
     application_task_runner_->PostTask(
         FROM_HERE,
         base::Bind(&Instance::BindServiceRequestOnApplicationThread, this,
                    base::Passed(&request)));
   }
 
   void ShutDown() {
     DCHECK(runner_thread_checker_.CalledOnValidThread());
     if (thread_) {
+      thread_.reset();
       application_task_runner_ = nullptr;
-      thread_.reset();
     }
   }
 
  private:
   void BindServiceRequestOnApplicationThread(
       shell::mojom::ServiceRequest request) {
     DCHECK(application_task_runner_->BelongsToCurrentThread());
 
     if (!service_) {
       service_ = factory_callback_.Run(
@@ skipping 89 matching lines @@
     const base::Closure& quit_closure) {
   quit_closure_ = quit_closure;
 }
 
 void EmbeddedApplicationRunner::OnQuit() {
   if (!quit_closure_.is_null())
     quit_closure_.Run();
 }
 
 }  // namespace content