[NO SUBMIT] Battery Status API skeleton implementation ASYNC

content/browser/battery_status/battery_status_service.h

+// Copyright 2013 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 CONTENT_BROWSER_BATTERY_STATUS_BATTERY_STATUS_SERVICE_H_
+#define CONTENT_BROWSER_BATTERY_STATUS_BATTERY_STATUS_SERVICE_H_
+
+#include "base/callback_forward.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/singleton.h"
+#include "content/common/content_export.h"
+
+#include "content/browser/battery_status/battery_status_manager_android.h"
+#include <vector>
+
+#include "third_party/WebKit/public/platform/WebBatteryStatus.h"
+
+namespace content {
+
+class CONTENT_EXPORT BatteryStatusService {
+ public:
+  // Returns the BatteryStatusService singleton.
+  static BatteryStatusService* GetInstance();
+
+  typedef base::Callback<void(const blink::WebBatteryStatus&)> BatteryStatusUpdateCallback;
+
+  // Adds a callback to receive battery status updates.
+  // Must be called on the I/O thread.
+  void AddConsumer(const BatteryStatusUpdateCallback& callback);
+
+  // Removes a callback. Must be called on the I/O thread.
+  void RemoveConsumer(const BatteryStatusUpdateCallback& callback);
+
+  // TODO: is this needed?
+  void Shutdown();
+
+  // Injects a custom battery status manager for testing purposes. This class takes
+  // ownership of the injected object.
+  //void SetDataFetcherForTests(BatteryStatusManager* test_data_fetcher);
+
+  void UpdateBatteryStatus(bool charging, double chargingTime, double dischargingTime, double level);
+  const blink::WebBatteryStatus& GetBatteryStatus() const;
+
+ private:
+  friend struct DefaultSingletonTraits<BatteryStatusService>;
+
+  BatteryStatusService();
+  virtual ~BatteryStatusService();
+
+  void NotifyConsumers();
+
+  bool is_shutdown_;
+  scoped_ptr<BatteryStatusManagerAndroid> battery_fetcher_;
+  std::vector<BatteryStatusUpdateCallback> callbacks_;
+  blink::WebBatteryStatus status_;
+
+  DISALLOW_COPY_AND_ASSIGN(BatteryStatusService);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_BATTERY_STATUS_BATTERY_STATUS_SERVICE_H_