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

Source/modules/device_light/DeviceLightDispatcher.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 DeviceLightDispatcher_h
 #define DeviceLightDispatcher_h
 
-#include "core/frame/DeviceSensorEventDispatcher.h"
+#include "core/frame/DeviceEventDispatcherBase.h"
 #include "public/platform/WebDeviceLightListener.h"
 #include "wtf/RefPtr.h"
 
 namespace WebCore {
 
 class DeviceLightController;
 
-// This class listens to device light data and dispatches it to all
-// listening controllers
-class DeviceLightDispatcher FINAL : public DeviceSensorEventDispatcher, public blink::WebDeviceLightListener {
+// This class listens to device light data and notifies all registered controllers.
+class DeviceLightDispatcher FINAL : public DeviceEventDispatcherBase, public blink::WebDeviceLightListener {
 public:
     static DeviceLightDispatcher& instance();
 
     double latestDeviceLightData() const;
 
-    // This method is called every time new device light data is available.
+    // Inherited from WebDeviceLightListener.
     virtual void didChangeDeviceLight(double) OVERRIDE;
-    void addDeviceLightController(DeviceLightController*);
-    void removeDeviceLightController(DeviceLightController*);
 
 private:
     DeviceLightDispatcher();
     virtual ~DeviceLightDispatcher();
 
+    // Inherited from DeviceEventDispatcherBase.
     virtual void startListening() OVERRIDE;
     virtual void stopListening() OVERRIDE;
 
     double m_lastDeviceLightData;
 };
 
 } // namespace WebCore
 
 #endif // DeviceLightDispatcher_h