Oilpan: Prepare to support garbage-collected Node in WebNode hierarchy.

Source/web/ChromeClientImpl.cpp

Index: Source/web/ChromeClientImpl.cpp
diff --git a/Source/web/ChromeClientImpl.cpp b/Source/web/ChromeClientImpl.cpp
index 4e8c2bbd2c2534fe570895ff3917bfced9da9bf7..1b07f7c28eb2ffeb042873dc411f559fb1b49c0b 100644
--- a/Source/web/ChromeClientImpl.cpp
+++ b/Source/web/ChromeClientImpl.cpp
@@ -852,7 +852,7 @@ void ChromeClientImpl::didAssociateFormControls(const Vector<RefPtr<Element> >&
     WebVector<WebNode> elementVector(static_cast<size_t>(elements.size()));
     size_t elementsCount = elements.size();
     for (size_t i = 0; i < elementsCount; ++i)
-        elementVector[i] = elements[i];
+        elementVector[i] = elements[i].get();
     m_webView->autofillClient()->didAssociateFormControls(elementVector);
 }