Remove DeviceMonitorLinux::WillDestroyCurrentMessageLoop().

device/usb/usb_service_linux.h

 // 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 <list>
+#include <memory>
 #include <unordered_map>
 
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "device/usb/usb_service.h"
 
 namespace base {
 class SequencedTaskRunner;
 class SingleThreadTaskRunner;
 }
 
 namespace device {
 
 struct UsbDeviceDescriptor;
 class UsbDeviceLinux;
 
 class UsbServiceLinux : public UsbService {
  public:
   explicit UsbServiceLinux(
-      scoped_refptr<base::SequencedTaskRunner> blocking_task_runner);
+      scoped_refptr<base::SequencedTaskRunner> blocking_task_runner_in);
   ~UsbServiceLinux() override;
 
   // device::UsbService implementation
+  void Shutdown() override;
   void GetDevices(const GetDevicesCallback& callback) override;
 
  private:
   using DeviceMap =
       std::unordered_map<std::string, scoped_refptr<UsbDeviceLinux>>;
 
   class FileThreadHelper;
 
   void OnDeviceAdded(const std::string& device_path,
                      const UsbDeviceDescriptor& descriptor,
@@ skipping 11 matching lines @@
 
   // |helper_started_| is set once OnDeviceAdded has been called for all devices
   // initially found on the system. |first_enumeration_countdown_| is then
   // decremented as DeviceReady is called for these devices.
   // |enumeration_callbacks_| holds the callbacks passed to GetDevices before
   // this process completes and the device list is ready.
   bool helper_started_ = false;
   uint32_t first_enumeration_countdown_ = 0;
   std::list<GetDevicesCallback> enumeration_callbacks_;
 
-  FileThreadHelper* helper_;
+  std::unique_ptr<FileThreadHelper> helper_;
   DeviceMap devices_by_path_;
 
   base::WeakPtrFactory<UsbServiceLinux> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(UsbServiceLinux);
 };
 
 }  // namespace device