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

Source/core/html/HTMLKeygenElement.cpp

Index: Source/core/html/HTMLKeygenElement.cpp
diff --git a/Source/core/html/HTMLKeygenElement.cpp b/Source/core/html/HTMLKeygenElement.cpp
index 0fb9dc10333284351cedc6f2d076d19eaf6a5de3..73a58342093b9ded1d4c7f1cc82223cb4883d56c 100644
--- a/Source/core/html/HTMLKeygenElement.cpp
+++ b/Source/core/html/HTMLKeygenElement.cpp
@@ -57,10 +57,10 @@ void HTMLKeygenElement::didAddUserAgentShadowRoot(ShadowRoot& root)
     getSupportedKeySizes(locale(), keys);
 
     // Create a select element with one option element for each key size.
-    RefPtr<HTMLSelectElement> select = HTMLSelectElement::create(document());
+    RefPtrWillBeRawPtr<HTMLSelectElement> select = HTMLSelectElement::create(document());
     select->setShadowPseudoId(keygenSelectPseudoId);
     for (size_t i = 0; i < keys.size(); ++i) {
-        RefPtr<HTMLOptionElement> option = HTMLOptionElement::create(document());
+        RefPtrWillBeRawPtr<HTMLOptionElement> option = HTMLOptionElement::create(document());
         option->appendChild(Text::create(document(), keys[i]));
         select->appendChild(option);
     }