Generalize and refactor DeviceSensorEvent* architecture to support multi-event type targets.

Source/modules/battery/BatteryDispatcher.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 BatteryDispatcher_h
 #define BatteryDispatcher_h
 
-#include "core/frame/DeviceSensorEventDispatcher.h"
+#include "core/frame/DeviceEventDispatcherBase.h"
 #include "modules/battery/BatteryManager.h"
 #include "modules/battery/BatteryStatus.h"
 #include "public/platform/WebBatteryStatusListener.h"
 
 namespace blink {
 class WebBatteryStatus;
 }
 
 namespace WebCore {
 
-class BatteryDispatcher FINAL : public DeviceSensorEventDispatcher, public blink::WebBatteryStatusListener {
+class BatteryDispatcher FINAL : public DeviceEventDispatcherBase, public blink::WebBatteryStatusListener {
 public:
     static BatteryDispatcher& instance();
     virtual ~BatteryDispatcher();
 
-    void addClient(BatteryManager*);
-    void removeClient(BatteryManager*);
+    BatteryStatus* latestData();
 
-    const BatteryStatus* getLatestData();
+    // Inherited from blink::WebBatteryStatusListener.
     virtual void updateBatteryStatus(const blink::WebBatteryStatus&) OVERRIDE;
 
 private:
     BatteryDispatcher();
 
-    void didChangeBatteryStatus(const AtomicString& eventType);
-
+    // Inherited from DeviceEventDispatcherBase.
     virtual void startListening() OVERRIDE;
     virtual void stopListening() OVERRIDE;
 
     RefPtr<BatteryStatus> m_batteryStatus;
 };
 
 }
 
 #endif // BatteryDispatcher_h