Introduce HTMLDataListOptionsCollection subclass for HTMLCollection

Source/core/html/HTMLDataListElement.h

Index: Source/core/html/HTMLDataListElement.h
diff --git a/Source/core/html/HTMLDataListElement.h b/Source/core/html/HTMLDataListElement.h
index de0df60947e8cf2fbcd2f7172e4d8ffb988b116e..a97be23a840c9eca83648678bba3a240e1e32088 100644
--- a/Source/core/html/HTMLDataListElement.h
+++ b/Source/core/html/HTMLDataListElement.h
@@ -32,16 +32,17 @@
 #ifndef HTMLDataListElement_h
 #define HTMLDataListElement_h
 
-#include "core/html/HTMLCollection.h"
 #include "core/html/HTMLElement.h"
 
 namespace blink {
 
+class HTMLDataListOptionsCollection;
+
 class HTMLDataListElement FINAL : public HTMLElement {
 public:
     static PassRefPtrWillBeRawPtr<HTMLDataListElement> create(Document&);
 
-    PassRefPtrWillBeRawPtr<HTMLCollection> options();
+    PassRefPtrWillBeRawPtr<HTMLDataListOptionsCollection> options();
 
     void optionElementChildrenChanged();