Fix invalid DCHECK in EmbeddedApplicationRunner

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 12 matching lines @@
   Instance(const base::StringPiece& name,
            const MojoApplicationInfo& info,
            const base::Closure& quit_closure)
       : name_(name.as_string()),
         factory_callback_(info.application_factory),
         use_own_thread_(!info.application_task_runner && info.use_own_thread),
         quit_closure_(quit_closure),
         quit_task_runner_(base::ThreadTaskRunnerHandle::Get()),
         application_task_runner_(info.application_task_runner) {
     application_thread_checker_.DetachFromThread();
-
     if (!use_own_thread_ && !application_task_runner_)
       application_task_runner_ = base::ThreadTaskRunnerHandle::Get();
   }
 
   void BindShellClientRequest(shell::mojom::ShellClientRequest request) {
     DCHECK(runner_thread_checker_.CalledOnValidThread());
 
     if (use_own_thread_ && !thread_) {
       // Start a new thread if necessary.
       thread_.reset(new base::Thread(name_));
       thread_->Start();
       application_task_runner_ = thread_->task_runner();
+      application_thread_checker_.DetachFromThread();
     }
 
     DCHECK(application_task_runner_);
     application_task_runner_->PostTask(
         FROM_HERE,
         base::Bind(&Instance::BindShellClientRequestOnApplicationThread, this,
                    base::Passed(&request)));
   }
 
   void ShutDown() {
@@ skipping 63 matching lines @@
   const bool use_own_thread_;
   const base::Closure quit_closure_;
   const scoped_refptr<base::SingleThreadTaskRunner> quit_task_runner_;
 
   // Thread checker used to ensure certain operations happen only on the
   // runner's (i.e. our owner's) thread.
   base::ThreadChecker runner_thread_checker_;
 
   // Thread checker used to ensure certain operations happen only on the
   // application task runner's thread.
   base::ThreadChecker application_thread_checker_;

[xhwang, 2016/05/25 17:30:27]

Does it make sense to just use 

application_task_runner_->BelongsToCurrentThread()

to check whether certain operation is run on the application task runner's
thread?

 
   // These fields must only be accessed from the runner's thread.
   std::unique_ptr<base::Thread> thread_;
   scoped_refptr<base::SingleThreadTaskRunner> application_task_runner_;
 
   // These fields must only be accessed from the application thread, except in
   // the destructor which may run on either the runner thread or the application
   // thread.
   std::unique_ptr<shell::ShellClient> shell_client_;
   std::vector<std::unique_ptr<shell::ShellConnection>> shell_connections_;
@@ skipping 23 matching lines @@
     const base::Closure& quit_closure) {
   quit_closure_ = quit_closure;
 }
 
 void EmbeddedApplicationRunner::OnQuit() {
   if (!quit_closure_.is_null())
     quit_closure_.Run();
 }
 
 }  // namespace content