Revert of Add U2F request state machines

device/u2f/u2f_request.h

Index: device/u2f/u2f_request.h
diff --git a/device/u2f/u2f_request.h b/device/u2f/u2f_request.h
deleted file mode 100644
index 902a2ca84d6f51275e2a93b97c9c37a6722dff72..0000000000000000000000000000000000000000
--- a/device/u2f/u2f_request.h
+++ /dev/null
@@ -1,65 +0,0 @@
-// Copyright 2017 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_U2F_U2F_REQUEST_H_
-#define DEVICE_U2F_U2F_REQUEST_H_
-
-#include "base/cancelable_callback.h"
-#include "base/scoped_observer.h"
-#include "device/hid/hid_device_filter.h"
-#include "device/hid/hid_service.h"
-#include "u2f_device.h"
-
-namespace device {
-class U2fRequest : HidService::Observer {
- public:
-  using ResponseCallback = base::Callback<void(U2fReturnCode status_code,
-                                               std::vector<uint8_t> response)>;
-
-  U2fRequest(const ResponseCallback& callback);
-  virtual ~U2fRequest();
-
-  void Start();
-  void AddDeviceForTesting(std::unique_ptr<U2fDevice> device);
-
- protected:
-  enum class State {
-    INIT,
-    BUSY,
-    WINK,
-    IDLE,
-    OFF,
-    COMPLETE,
-  };
-
-  void Transition();
-  virtual void TryDevice() = 0;
-
-  std::unique_ptr<U2fDevice> current_device_;
-  State state_;
-  ResponseCallback cb_;
-
- private:
-  FRIEND_TEST_ALL_PREFIXES(U2fRequestTest, TestAddRemoveDevice);
-  FRIEND_TEST_ALL_PREFIXES(U2fRequestTest, TestIterateDevice);
-  FRIEND_TEST_ALL_PREFIXES(U2fRequestTest, TestBasicMachine);
-
-  void Enumerate();
-  void IterateDevice();
-  void OnWaitComplete();
-  void AddDevice(std::unique_ptr<U2fDevice> device);
-  void OnDeviceAdded(scoped_refptr<HidDeviceInfo> device_info) override;
-  void OnDeviceRemoved(scoped_refptr<HidDeviceInfo> device_info) override;
-  void OnEnumerate(const std::vector<scoped_refptr<HidDeviceInfo>>& devices);
-
-  std::list<std::unique_ptr<U2fDevice>> devices_;
-  std::list<std::unique_ptr<U2fDevice>> attempted_devices_;
-  base::CancelableClosure delay_callback_;
-  HidDeviceFilter filter_;
-  ScopedObserver<HidService, HidService::Observer> hid_service_observer_;
-  base::WeakPtrFactory<U2fRequest> weak_factory_;
-};
-}  // namespace device
-
-#endif  // DEVICE_U2F_U2F_REQUEST_H_