Make it clear a DocumentNameCollection can only contain HTMLElements

Source/bindings/core/v8/WindowProxy.cpp

Index: Source/bindings/core/v8/WindowProxy.cpp
diff --git a/Source/bindings/core/v8/WindowProxy.cpp b/Source/bindings/core/v8/WindowProxy.cpp
index 5e5f04e185509e3b551674ef1d585fa7af12e5eb..a43a585de193b0ae502c7b5e675ac2a41dd4cc05 100644
--- a/Source/bindings/core/v8/WindowProxy.cpp
+++ b/Source/bindings/core/v8/WindowProxy.cpp
@@ -45,6 +45,7 @@
 #include "bindings/core/v8/V8Window.h"
 #include "core/frame/LocalFrame.h"
 #include "core/frame/csp/ContentSecurityPolicy.h"
+#include "core/html/DocumentNameCollection.h"
 #include "core/html/HTMLCollection.h"
 #include "core/html/HTMLIFrameElement.h"
 #include "core/inspector/InspectorInstrumentation.h"
@@ -417,12 +418,12 @@ static v8::Handle<v8::Value> getNamedProperty(HTMLDocument* htmlDocument, const
     if (!htmlDocument->hasNamedItem(key) && !htmlDocument->hasExtraNamedItem(key))
         return v8Undefined();
 
-    RefPtrWillBeRawPtr<HTMLCollection> items = htmlDocument->documentNamedItems(key);
+    RefPtrWillBeRawPtr<DocumentNameCollection> items = htmlDocument->documentNamedItems(key);
     if (items->isEmpty())
         return v8Undefined();
 
     if (items->hasExactlyOneItem()) {
-        Element* element = items->item(0);
+        HTMLElement* element = items->item(0);
         ASSERT(element);
         Frame* frame = isHTMLIFrameElement(*element) ? toHTMLIFrameElement(*element).contentFrame() : 0;
         if (frame)