Reland "Replace Chrome IPC with Mojo IPC for querying BatteryStatus service"

device/battery/battery_status_service.h

 // 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_
+#ifndef DEVICE_BATTERY_BATTERY_STATUS_SERVICE_H_
+#define DEVICE_BATTERY_BATTERY_STATUS_SERVICE_H_
 
 #include "base/callback_list.h"
+#include "base/memory/scoped_ptr.h"
 #include "base/memory/singleton.h"
-#include "content/common/content_export.h"
-#include "third_party/WebKit/public/platform/WebBatteryStatus.h"
+#include "device/battery/battery_export.h"
+#include "device/battery/battery_status.mojom.h"
 
-namespace content {
+namespace base {
+class SingleThreadTaskRunner;
+}
+
+namespace device {
 class BatteryStatusManager;
 
-class CONTENT_EXPORT BatteryStatusService {
+class DEVICE_BATTERY_EXPORT BatteryStatusService {
  public:
-  typedef base::Callback<void(const blink::WebBatteryStatus&)>
-      BatteryUpdateCallback;
-  typedef base::CallbackList<void(const blink::WebBatteryStatus&)>
+  typedef base::Callback<void(const BatteryStatus&)> BatteryUpdateCallback;
+  typedef base::CallbackList<void(const BatteryStatus&)>
       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.
+  // Adds a callback to receive battery status updates.  Must be called on the
+  // main thread. The callback itself will be called on the main thread as well.
   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);
+  void SetBatteryManagerForTesting(
+      scoped_ptr<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 NotifyConsumers(const BatteryStatus& status);
+  void NotifyConsumersOnMainThread(const BatteryStatus& status);
   void ConsumersChanged();
 
+  scoped_refptr<base::SingleThreadTaskRunner> main_thread_task_runner_;
   scoped_ptr<BatteryStatusManager> battery_fetcher_;
   BatteryUpdateCallbackList callback_list_;
   BatteryUpdateCallback update_callback_;
-  blink::WebBatteryStatus status_;
+  BatteryStatus status_;
   bool status_updated_;
   bool is_shutdown_;
 
   DISALLOW_COPY_AND_ASSIGN(BatteryStatusService);
 };
 
-}  // namespace content
+}  // namespace device
 
-#endif  // CONTENT_BROWSER_BATTERY_STATUS_BATTERY_STATUS_SERVICE_H_
+#endif  // DEVICE_BATTERY_BATTERY_STATUS_SERVICE_H_