SinglyLinkedList: Rename Size to Count.

So that it has the same naming as DoublyLinkedList.
No functional change. It seems there aren't any users
of this API in the default build at the moment.

headers/private/kernel/util/SinglyLinkedList.h

@@ -161,7 +161,7 @@ class SinglyLinkedList {
 
 		inline Element* GetNext(Element* element) const;
 
-		inline int32 Size() const;
+		inline int32 Count() const;
 			// O(n)!
 
 		inline Iterator GetIterator() const	{ return Iterator(this); }
@@ -300,7 +300,7 @@ SINGLY_LINKED_LIST_CLASS_NAME::GetNext(Element* element) const
 // Size
 SINGLY_LINKED_LIST_TEMPLATE_LIST
 int32
-SINGLY_LINKED_LIST_CLASS_NAME::Size() const
+SINGLY_LINKED_LIST_CLASS_NAME::Count() const
 {
 	int32 count = 0;
 	for (Element* element = First(); element; element = GetNext(element))