Oilpan: Allocate all EventTarget derived types on the manged heap.

Source/modules/battery/BatteryManager.h

Index: Source/modules/battery/BatteryManager.h
diff --git a/Source/modules/battery/BatteryManager.h b/Source/modules/battery/BatteryManager.h
index 13148d5d360a0dc997fa605b84ce0c6920157f6b..875f9c9db9a23db028c6c283c900af5490444342 100644
--- a/Source/modules/battery/BatteryManager.h
+++ b/Source/modules/battery/BatteryManager.h
@@ -16,7 +16,8 @@ namespace WebCore {
 class Navigator;
 
 class BatteryManager FINAL : public RefCountedWillBeRefCountedGarbageCollected<BatteryManager>, public ActiveDOMObject, public DeviceSensorEventController, public EventTargetWithInlineData {
-    DEFINE_EVENT_TARGET_REFCOUNTING(RefCountedWillBeRefCountedGarbageCollected<BatteryManager>);
+    REFCOUNTED_EVENT_TARGET(BatteryManager);
+    WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(BatteryManager);
 public:
     virtual ~BatteryManager();
     static PassRefPtrWillBeRawPtr<BatteryManager> create(ExecutionContext*);
@@ -51,8 +52,6 @@ public:
     virtual bool isNullEvent(Event*) OVERRIDE;
     virtual Document* document() OVERRIDE;
 
-    void trace(Visitor*) { }
-
 private:
     explicit BatteryManager(ExecutionContext*);
 };