[DeviceService] Expose battery monitoring solely via the Device Service

device/battery/battery_status_manager_default.cc

-// 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.
-
-#include "device/battery/battery_status_manager.h"
-
-#include <memory>
-
-#include "base/logging.h"
-#include "base/macros.h"
-
-namespace device {
-
-namespace {
-
-class BatteryStatusManagerDefault : public BatteryStatusManager {
- public:
-  explicit BatteryStatusManagerDefault(
-      const BatteryStatusService::BatteryUpdateCallback& callback) {}
-  ~BatteryStatusManagerDefault() override {}
-
- private:
-  // BatteryStatusManager:
-  bool StartListeningBatteryChange() override {
-    NOTIMPLEMENTED();
-    return false;
-  }
-
-  void StopListeningBatteryChange() override { NOTIMPLEMENTED(); }
-
-  DISALLOW_COPY_AND_ASSIGN(BatteryStatusManagerDefault);
-};
-
-}  // namespace
-
-// static
-std::unique_ptr<BatteryStatusManager> BatteryStatusManager::Create(
-    const BatteryStatusService::BatteryUpdateCallback& callback) {
-  return std::unique_ptr<BatteryStatusManager>(
-      new BatteryStatusManagerDefault(callback));
-}
-
-}  // namespace device