Remove DeviceMonitorLinux::WillDestroyCurrentMessageLoop().

device/usb/usb_service.cc

 // Copyright 2015 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 "device/usb/usb_service.h"
 
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/memory/ptr_util.h"
 #include "base/threading/thread_task_runner_handle.h"
@@ skipping 33 matching lines @@
 #elif defined(USE_UDEV)
   return base::WrapUnique(new UsbServiceLinux(blocking_task_runner));
 #elif defined(OS_WIN) || defined(OS_MACOSX)
   return base::WrapUnique(new UsbServiceImpl(blocking_task_runner));
 #else
   return nullptr;
 #endif
 }
 
 UsbService::~UsbService() {
+#if DCHECK_IS_ON()
+  DCHECK(did_shutdown_);
+#endif
   for (const auto& map_entry : devices_)
     map_entry.second->OnDisconnect();
   for (auto& observer : observer_list_)
     observer.WillDestroyUsbService();
 }
 
 UsbService::UsbService(
     scoped_refptr<base::SingleThreadTaskRunner> task_runner,
     scoped_refptr<base::SequencedTaskRunner> blocking_task_runner)
     : task_runner_(task_runner), blocking_task_runner_(blocking_task_runner) {}
 
 scoped_refptr<UsbDevice> UsbService::GetDevice(const std::string& guid) {
   DCHECK(CalledOnValidThread());
   auto it = devices_.find(guid);
   if (it == devices_.end())
     return nullptr;
   return it->second;
 }
 
+void UsbService::Shutdown() {
+#if DCHECK_IS_ON()
+  DCHECK(!did_shutdown_);
+  did_shutdown_ = true;
+#endif
+}
+
 void UsbService::GetDevices(const GetDevicesCallback& callback) {
   std::vector<scoped_refptr<UsbDevice>> devices;
   devices.reserve(devices_.size());
   for (const auto& map_entry : devices_)
     devices.push_back(map_entry.second);
   if (task_runner_)
     task_runner_->PostTask(FROM_HERE, base::Bind(callback, devices));
   else
     callback.Run(devices);
 }
@@ skipping 53 matching lines @@
   DCHECK(CalledOnValidThread());
 
   for (auto& observer : observer_list_)
     observer.OnDeviceRemoved(device);
   device->NotifyDeviceRemoved();
   for (auto& observer : observer_list_)
     observer.OnDeviceRemovedCleanup(device);
 }
 
 }  // namespace device