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

Source/web/WebSelectElement.cpp

Index: Source/web/WebSelectElement.cpp
diff --git a/Source/web/WebSelectElement.cpp b/Source/web/WebSelectElement.cpp
index ec0c8ce005314a96efd00cf259cf3d1301c54052..4cec6166736e4e83c97494c217bfd27aeee81fd3 100644
--- a/Source/web/WebSelectElement.cpp
+++ b/Source/web/WebSelectElement.cpp
@@ -43,10 +43,10 @@ namespace blink {
 
 WebVector<WebElement> WebSelectElement::listItems() const
 {
-    const Vector<HTMLElement*>& sourceItems = constUnwrap<HTMLSelectElement>()->listItems();
+    const WillBeHeapVector<RawPtrWillBeMember<HTMLElement> >& sourceItems = constUnwrap<HTMLSelectElement>()->listItems();
     WebVector<WebElement> items(sourceItems.size());
     for (size_t i = 0; i < sourceItems.size(); ++i)
-        items[i] = WebElement(sourceItems[i]);
+        items[i] = WebElement(sourceItems[i].get());
 
     return items;
 }