Create and remove |UiDevToolsServer::server_| in the same thread.

components/ui_devtools/devtools_server.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 "components/ui_devtools/devtools_server.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "base/format_macros.h"
@@ skipping 47 matching lines @@
     return;
   // If io_thread_task_runner not passed in, create an I/O thread
   thread_.reset(new base::Thread("UiDevToolsServerThread"));
   base::Thread::Options options;
   options.message_loop_type = base::MessageLoop::TYPE_IO;
   CHECK(thread_->StartWithOptions(options));
   io_thread_task_runner_ = thread_->task_runner();
 }
 
 UiDevToolsServer::~UiDevToolsServer() {
+  if (io_thread_task_runner_)
+    io_thread_task_runner_->DeleteSoon(FROM_HERE, server_.release());
+  if (thread_->IsRunning())

[sadrul, 2017/06/28 04:49:10]

You should check if |thread|_ is non-null first.

[thanhph, 2017/06/28 14:38:22]

Done.

+    thread_->Stop();
   devtools_server_ = nullptr;
 }
 
 // static
 std::unique_ptr<UiDevToolsServer> UiDevToolsServer::Create(
     scoped_refptr<base::SingleThreadTaskRunner> io_thread_task_runner) {
   std::unique_ptr<UiDevToolsServer> server;
   if (IsUiDevToolsEnabled() && !devtools_server_) {
     // TODO(mhashmi): Change port if more than one inspectable clients
     server.reset(new UiDevToolsServer(io_thread_task_runner));
@@ skipping 97 matching lines @@
     return;
   UiDevToolsClient* client = it->second;
   DCHECK(client);
   main_thread_task_runner_->PostTask(
       FROM_HERE,
       base::Bind(&UiDevToolsClient::Disconnect, base::Unretained(client)));
   connections_.erase(it);
 }
 
 }  // namespace ui_devtools