Oilpan: Prepare to move FormAssociatedElement to Oilpan heap, part 1.

Source/core/html/HTMLObjectElement.cpp

Index: Source/core/html/HTMLObjectElement.cpp
diff --git a/Source/core/html/HTMLObjectElement.cpp b/Source/core/html/HTMLObjectElement.cpp
index faf7cb33c5817f32492ef95d04533f70be702dfc..a7194104d0972854e979ac61252fd4d14b19eee4 100644
--- a/Source/core/html/HTMLObjectElement.cpp
+++ b/Source/core/html/HTMLObjectElement.cpp
@@ -70,6 +70,12 @@ PassRefPtrWillBeRawPtr<HTMLObjectElement> HTMLObjectElement::create(Document& do
     return element.release();
 }
 
+void HTMLObjectElement::trace(Visitor* visitor)
+{
+    FormAssociatedElement::trace(visitor);
+    HTMLPlugInElement::trace(visitor);
+}
+
 RenderWidget* HTMLObjectElement::existingRenderWidget() const
 {
     return renderPart(); // This will return 0 if the renderer is not a RenderPart.