Manage HidService lifetime in DeviceClient implementations.

device/hid/hid_service_win.h

Index: device/hid/hid_service_win.h
diff --git a/device/hid/hid_service_win.h b/device/hid/hid_service_win.h
index b5b081d6590f0f2a79808796ca06f57e4b332888..ad862510183d5aa46b12968081914248bbafc84e 100644
--- a/device/hid/hid_service_win.h
+++ b/device/hid/hid_service_win.h
@@ -32,13 +32,12 @@ namespace device {
 class HidServiceWin : public HidService, public DeviceMonitorWin::Observer {
  public:
   HidServiceWin(scoped_refptr<base::SingleThreadTaskRunner> file_task_runner);
+  ~HidServiceWin() override;
 
   void Connect(const HidDeviceId& device_id,
                const ConnectCallback& callback) override;
 
  private:
-  ~HidServiceWin() override;
-
   static void EnumerateOnFileThread(
       base::WeakPtr<HidServiceWin> service,
       scoped_refptr<base::SingleThreadTaskRunner> task_runner);