Oilpan: Prepare to move select and option elements to Oilpan heap.

Source/core/html/HTMLOptionElement.cpp

Index: Source/core/html/HTMLOptionElement.cpp
diff --git a/Source/core/html/HTMLOptionElement.cpp b/Source/core/html/HTMLOptionElement.cpp
index 5311478d6f891bee99a3ec287305ab9e471fbb13..29512a1a49d130ef8c8c82d29bde8b9c780f13f2 100644
--- a/Source/core/html/HTMLOptionElement.cpp
+++ b/Source/core/html/HTMLOptionElement.cpp
@@ -162,12 +162,12 @@ int HTMLOptionElement::index() const
 
     int optionIndex = 0;
 
-    const Vector<HTMLElement*>& items = selectElement->listItems();
+    const WillBeHeapVector<RawPtrWillBeMember<HTMLElement> >& items = selectElement->listItems();
     size_t length = items.size();
     for (size_t i = 0; i < length; ++i) {
         if (!isHTMLOptionElement(*items[i]))
             continue;
-        if (items[i] == this)
+        if (items[i].get() == this)
             return optionIndex;
         ++optionIndex;
     }