[oilpan] Completely move HTMLFormControlElement's hierarchy to the managed heap

Source/core/rendering/RenderFileUploadControl.h

Index: Source/core/rendering/RenderFileUploadControl.h
diff --git a/Source/core/rendering/RenderFileUploadControl.h b/Source/core/rendering/RenderFileUploadControl.h
index eb19aa7fb68a94e0e78b79de87e96712999c4b66..bc3631f7efbdc818c81f457ef51188735d384b82 100644
--- a/Source/core/rendering/RenderFileUploadControl.h
+++ b/Source/core/rendering/RenderFileUploadControl.h
@@ -33,7 +33,7 @@ class HTMLInputElement;
 
 class RenderFileUploadControl FINAL : public RenderBlock {
 public:
-    RenderFileUploadControl(HTMLInputElement*);
+    RenderFileUploadControl(Handle<HTMLInputElement>);
     virtual ~RenderFileUploadControl();
 
     virtual bool isFileUploadControl() const { return true; }
@@ -56,7 +56,7 @@ private:
     
     virtual VisiblePosition positionForPoint(const LayoutPoint&);
 
-    HTMLInputElement* uploadButton() const;
+    Result<HTMLInputElement> uploadButton() const;
 
     bool m_canReceiveDroppedFiles;
 };