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

Source/core/editing/DeleteSelectionCommand.cpp

Index: Source/core/editing/DeleteSelectionCommand.cpp
diff --git a/Source/core/editing/DeleteSelectionCommand.cpp b/Source/core/editing/DeleteSelectionCommand.cpp
index ef75f9bb567c335ca12e902224440e9d990afaa3..9849d7274e9f20fa7d35ddaa158f8686ec7753d7 100644
--- a/Source/core/editing/DeleteSelectionCommand.cpp
+++ b/Source/core/editing/DeleteSelectionCommand.cpp
@@ -794,7 +794,7 @@ void DeleteSelectionCommand::doApply()
 
     // If the deletion is occurring in a text field, and we're not deleting to replace the selection, then let the frame call across the bridge to notify the form delegate. 
     if (!m_replace) {
-        Element* textControl = enclosingTextFormControl(m_selectionToDelete.start());
+        Element* textControl = Handle<HTMLTextFormControlElement>(enclosingTextFormControl(m_selectionToDelete.start())).raw();
         if (textControl && textControl->focused())
             document()->frame()->editor()->textWillBeDeletedInTextField(textControl);
     }