Remove DeviceMonitorLinux::WillDestroyCurrentMessageLoop().

device/usb/usb_service.h

 // Copyright 2014 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.
 
 #ifndef DEVICE_USB_USB_SERVICE_H_
 #define DEVICE_USB_USB_SERVICE_H_
 
 #include <memory>
 #include <string>
 #include <unordered_map>
 #include <unordered_set>
 #include <vector>
 
 #include "base/bind_helpers.h"
+#include "base/logging.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/observer_list.h"
 #include "base/sequenced_task_runner.h"
 #include "base/single_thread_task_runner.h"
 #include "base/threading/non_thread_safe.h"
 
 namespace device {
 
 class UsbDevice;
@@ skipping 25 matching lines @@
 
   // The file task runner reference is used for blocking I/O operations.
   // Returns nullptr when initialization fails.
   static std::unique_ptr<UsbService> Create(
       scoped_refptr<base::SequencedTaskRunner> blocking_task_runner);
 
   virtual ~UsbService();
 
   scoped_refptr<UsbDevice> GetDevice(const std::string& guid);
 
+  // Shuts down the UsbService. Must be called before destroying the UsbService
+  // when tasks can still be posted to the |blocking_task_runner| provided to
+  // Create().
+  virtual void Shutdown();
+
   // Enumerates available devices.
   virtual void GetDevices(const GetDevicesCallback& callback);
 
   void AddObserver(Observer* observer);
   void RemoveObserver(Observer* observer);
 
   // Methods to add and remove devices for testing purposes. Only a device added
   // by this method can be removed by RemoveDeviceForTesting().
   void AddDeviceForTesting(scoped_refptr<UsbDevice> device);
   void RemoveDeviceForTesting(const std::string& device_guid);
@@ skipping 12 matching lines @@
 
   scoped_refptr<base::SequencedTaskRunner> blocking_task_runner() {
     return blocking_task_runner_;
   }
 
   std::unordered_map<std::string, scoped_refptr<UsbDevice>>& devices() {
     return devices_;
   }
 
  private:
-  friend void base::DeletePointer<UsbService>(UsbService* service);
-
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
   scoped_refptr<base::SequencedTaskRunner> blocking_task_runner_;
   std::unordered_map<std::string, scoped_refptr<UsbDevice>> devices_;
   std::unordered_set<std::string> testing_devices_;
   base::ObserverList<Observer, true> observer_list_;
 
+#if DCHECK_IS_ON()
+  bool did_shutdown_ = false;
+#endif
+
   DISALLOW_COPY_AND_ASSIGN(UsbService);
 };
 
 }  // namespace device
 
 #endif  // DEVICE_USB_USB_SERVICE_H_