Battery Status API: browser-side implementation.

content/browser/battery_status/battery_status_service.h

Index: content/browser/battery_status/battery_status_service.h
diff --git a/content/browser/battery_status/battery_status_service.h b/content/browser/battery_status/battery_status_service.h
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+// 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.
+
+#ifndef CONTENT_BROWSER_BATTERY_STATUS_BATTERY_STATUS_SERVICE_H_
+#define CONTENT_BROWSER_BATTERY_STATUS_BATTERY_STATUS_SERVICE_H_
+
+#include "base/callback_list.h"
+#include "base/memory/singleton.h"
+#include "content/common/content_export.h"
+#include "third_party/WebKit/public/platform/WebBatteryStatus.h"
+
+namespace content {
+class BatteryStatusManager;
+
+class CONTENT_EXPORT BatteryStatusService {
+ public:
+  typedef base::Callback<void(const blink::WebBatteryStatus&)>
+      BatteryUpdateCallback;
+  typedef base::CallbackList<void(const blink::WebBatteryStatus&)>
+      BatteryUpdateCallbackList;
+  typedef BatteryUpdateCallbackList::Subscription BatteryUpdateSubscription;
+
+  // Returns the BatteryStatusService singleton.
+  static BatteryStatusService* GetInstance();
+
+  // Adds a callback to receive battery status updates.
+  // Must be called on the I/O thread.
+  scoped_ptr<BatteryUpdateSubscription> AddCallback(
+      const BatteryUpdateCallback& callback);
+
+  // Gracefully clean-up.
+  void Shutdown();
+
+  // Injects a custom battery status manager for testing purposes.
+  // This class takes ownership of the injected object.
+  void SetBatteryManagerForTesting(BatteryStatusManager* test_battery_manager);
+
+  // Returns callback to invoke when battery is changed. Used for testing.
+  const BatteryUpdateCallback& GetUpdateCallbackForTesting() const;
+
+ private:
+  friend struct DefaultSingletonTraits<BatteryStatusService>;
+
+  BatteryStatusService();
+  virtual ~BatteryStatusService();
+
+  // Updates current battery status and sends new status to interested
+  // render processes. Can be called on any thread via a callback.
+  void UpdateBatteryStatus(const blink::WebBatteryStatus& status);
+  void NotifyConsumers(const blink::WebBatteryStatus& status);
+  void ConsumersChanged();
+
+  scoped_ptr<BatteryStatusManager> battery_fetcher_;
+  BatteryUpdateCallbackList callback_list_;
+  BatteryUpdateCallback update_callback_;
+  blink::WebBatteryStatus status_;
+  bool status_updated_;
+  bool is_shutdown_;
+
+  DISALLOW_COPY_AND_ASSIGN(BatteryStatusService);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_BATTERY_STATUS_BATTERY_STATUS_SERVICE_H_