[oilpan] Move EventHandler to the heap

Source/core/page/Frame.h

Index: Source/core/page/Frame.h
diff --git a/Source/core/page/Frame.h b/Source/core/page/Frame.h
index 66cb7b7875fd9296ec69b7d2ccfd19021a0408bf..d3e9e57e4b31ab79c8171e791f3c05629b6a07bf 100644
--- a/Source/core/page/Frame.h
+++ b/Source/core/page/Frame.h
@@ -97,7 +97,7 @@ namespace WebCore {
         FrameView* view() const;
 
         Editor* editor() const;
-        EventHandler* eventHandler() const;
+        RESULT(EventHandler) eventHandler() const;
         FrameLoader* loader() const;
         NavigationScheduler* navigationScheduler() const;
         FrameSelection* selection() const;
@@ -187,7 +187,7 @@ namespace WebCore {
         OwnPtr<ScriptController> m_script;
         OwnPtr<Editor> m_editor;
         OwnPtr<FrameSelection> m_selection;
-        OwnPtr<EventHandler> m_eventHandler;
+        ANNOTATED_FIELD(Persistent<EventHandler>, m_eventHandler);
         OwnPtr<AnimationController> m_animationController;
 
         float m_pageZoomFactor;
@@ -270,9 +270,9 @@ namespace WebCore {
         m_page = 0;
     }
 
-    inline EventHandler* Frame::eventHandler() const
+    inline RESULT(EventHandler) Frame::eventHandler() const
     {
-        return m_eventHandler.get();
+        return m_eventHandler;
     }
 
 } // namespace WebCore