Manage UsbService lifetime in DeviceClient implementations.

device/test/test_device_client.h

Index: device/test/test_device_client.h
diff --git a/device/test/test_device_client.h b/device/test/test_device_client.h
new file mode 100644
index 0000000000000000000000000000000000000000..ce70f3896880f68fa3237c99a75ea36a94b142e9
--- /dev/null
+++ b/device/test/test_device_client.h
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+// 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 "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
+#include "device/core/device_client.h"
+
+namespace base {
+class SingleThreadTaskRunner;
+}
+
+namespace device {
+
+class HidService;
+class UsbService;
+
+class TestDeviceClient : public DeviceClient {
+ public:
+  TestDeviceClient(scoped_refptr<base::SingleThreadTaskRunner> task_runner);
+  ~TestDeviceClient() override;
+
+ private:
+  HidService* GetHidService() override;
+  UsbService* GetUsbService() override;
+
+  scoped_ptr<UsbService> usb_service_;
+  scoped_refptr<base::SingleThreadTaskRunner> blocking_task_runner_;
+};
+
+}  // namespace device