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

Source/modules/battery/BatteryDispatcher.cpp

Index: Source/modules/battery/BatteryDispatcher.cpp
diff --git a/Source/modules/battery/BatteryDispatcher.cpp b/Source/modules/battery/BatteryDispatcher.cpp
index 707f27e1e73370bbed8841b42421ca8331218e38..515c49a7c6149a9c6c11f772f60d55bf1bede3f4 100644
--- a/Source/modules/battery/BatteryDispatcher.cpp
+++ b/Source/modules/battery/BatteryDispatcher.cpp
@@ -25,15 +25,61 @@
 {
 }
 
+void BatteryDispatcher::addClient(BatteryManager* batteryManager)
+{
+    addController(batteryManager);
+}
+
+void BatteryDispatcher::removeClient(BatteryManager* batteryManager)
+{
+    removeController(batteryManager);
+}
+
 void BatteryDispatcher::updateBatteryStatus(const blink::WebBatteryStatus& batteryStatus)
 {
+    RefPtr<BatteryStatus> oldStatus = m_batteryStatus;
     m_batteryStatus = BatteryStatus::create(batteryStatus.charging, batteryStatus.chargingTime, batteryStatus.dischargingTime, batteryStatus.level);
-    notifyControllers();
+
+    if (oldStatus) {
+        if (m_batteryStatus->charging() != oldStatus->charging())
+            didChangeBatteryStatus(EventTypeNames::chargingchange);
+        if (m_batteryStatus->charging() && m_batteryStatus->chargingTime() != oldStatus->chargingTime())
+            didChangeBatteryStatus(EventTypeNames::chargingtimechange);
+        if (!m_batteryStatus->charging() && m_batteryStatus->dischargingTime() != oldStatus->dischargingTime())
+            didChangeBatteryStatus(EventTypeNames::dischargingtimechange);
+        if (m_batteryStatus->level() != oldStatus->level())
+            didChangeBatteryStatus(EventTypeNames::levelchange);
+    } else {
+        // There was no previous state.
+        didChangeBatteryStatus(EventTypeNames::chargingchange);
+        didChangeBatteryStatus(EventTypeNames::chargingtimechange);
+        didChangeBatteryStatus(EventTypeNames::dischargingtimechange);
+        didChangeBatteryStatus(EventTypeNames::levelchange);
+    }
+
 }
 
-BatteryStatus* BatteryDispatcher::latestData()
+const BatteryStatus* BatteryDispatcher::getLatestData()
 {
     return m_batteryStatus.get();
+}
+
+void BatteryDispatcher::didChangeBatteryStatus(const AtomicString& eventType)
+{
+    RefPtrWillBeRawPtr<Event> event = Event::create(eventType);
+
+    {
+        TemporaryChange<bool> changeIsDispatching(m_isDispatching, true);
+        // Don't fire listeners removed or added during event dispatch.
+        size_t size = m_controllers.size();
+        for (size_t i = 0; i < size; ++i) {
+            if (m_controllers[i])
+                static_cast<BatteryManager*>(m_controllers[i])->didChangeBatteryStatus(event);
+        }
+    }
+
+    if (m_needsPurge)
+        purgeControllers();
 }
 
 void BatteryDispatcher::startListening()
@@ -44,7 +90,6 @@
 void BatteryDispatcher::stopListening()
 {
     blink::Platform::current()->setBatteryStatusListener(0);
-    m_batteryStatus.clear();
 }
 
 }