Move PlatformEventDispatcher implementations to the Oilpan heap.

Source/modules/device_light/DeviceLightDispatcher.h

Index: Source/modules/device_light/DeviceLightDispatcher.h
diff --git a/Source/modules/device_light/DeviceLightDispatcher.h b/Source/modules/device_light/DeviceLightDispatcher.h
index 7e0cb6fc67969836cbfded5e76510714aec4672f..fef082215ca3b240c3fd2be5a8a8ee764a5271e7 100644
--- a/Source/modules/device_light/DeviceLightDispatcher.h
+++ b/Source/modules/device_light/DeviceLightDispatcher.h
@@ -6,6 +6,7 @@
 #define DeviceLightDispatcher_h
 
 #include "core/frame/PlatformEventDispatcher.h"
+#include "platform/heap/Handle.h"
 #include "public/platform/WebDeviceLightListener.h"
 #include "wtf/RefPtr.h"
 
@@ -14,22 +15,25 @@ namespace blink {
 class DeviceLightController;
 
 // This class listens to device light data and notifies all registered controllers.
-class DeviceLightDispatcher FINAL : public PlatformEventDispatcher, public WebDeviceLightListener {
+class DeviceLightDispatcher final : public GarbageCollectedFinalized<DeviceLightDispatcher>, public PlatformEventDispatcher, public WebDeviceLightListener {
+    USING_GARBAGE_COLLECTED_MIXIN(DeviceLightDispatcher);
 public:
     static DeviceLightDispatcher& instance();
+    virtual ~DeviceLightDispatcher();
 
     double latestDeviceLightData() const;
 
     // Inherited from WebDeviceLightListener.
-    virtual void didChangeDeviceLight(double) OVERRIDE;
+    virtual void didChangeDeviceLight(double) override;
+
+    virtual void trace(Visitor*) override;
 
 private:
     DeviceLightDispatcher();
-    virtual ~DeviceLightDispatcher();
 
     // Inherited from PlatformEventDispatcher.
-    virtual void startListening() OVERRIDE;
-    virtual void stopListening() OVERRIDE;
+    virtual void startListening() override;
+    virtual void stopListening() override;
 
     double m_lastDeviceLightData;
 };