IDL: Use Nullable for union type return value

Source/core/html/HTMLAllCollection.cpp

Index: Source/core/html/HTMLAllCollection.cpp
diff --git a/Source/core/html/HTMLAllCollection.cpp b/Source/core/html/HTMLAllCollection.cpp
index d434abdfbf4df45aede64dc6064fbc12664db587..cf4ce61f75f4c715b3826bd3f76f2bbb9a9e523a 100644
--- a/Source/core/html/HTMLAllCollection.cpp
+++ b/Source/core/html/HTMLAllCollection.cpp
@@ -66,7 +66,7 @@ Element* HTMLAllCollection::namedItemWithIndex(const AtomicString& name, unsigne
     return 0;
 }
 
-void HTMLAllCollection::namedGetter(const AtomicString& name, bool& returnValue0Enabled, RefPtrWillBeRawPtr<NodeList>& returnValue0, bool& returnValue1Enabled, RefPtrWillBeRawPtr<Element>& returnValue1)
+void HTMLAllCollection::namedGetter(const AtomicString& name, RefPtrWillBeRawPtr<NodeList>& returnValue0, RefPtrWillBeRawPtr<Element>& returnValue1)
 {
     WillBeHeapVector<RefPtrWillBeMember<Element> > namedItems;
     this->namedItems(name, namedItems);
@@ -75,14 +75,12 @@ void HTMLAllCollection::namedGetter(const AtomicString& name, bool& returnValue0
         return;
 
     if (namedItems.size() == 1) {
-        returnValue1Enabled = true;
         returnValue1 = namedItems.at(0);
         return;
     }
 
     // FIXME: HTML5 specification says this should be a HTMLCollection.
     // http://www.whatwg.org/specs/web-apps/current-work/multipage/common-dom-interfaces.html#htmlallcollection
-    returnValue0Enabled = true;
     returnValue0 = StaticElementList::adopt(namedItems);
 }