Rename CollectionIndexCache API to not use 'Element'

Source/core/dom/LiveNodeList.cpp

Index: Source/core/dom/LiveNodeList.cpp
diff --git a/Source/core/dom/LiveNodeList.cpp b/Source/core/dom/LiveNodeList.cpp
index 94f300eb63a5da533d7edd5a9fae1fa08cc299bb..2254a728c26eb17bf8acc463e7dbb629a0b6dfc7 100644
--- a/Source/core/dom/LiveNodeList.cpp
+++ b/Source/core/dom/LiveNodeList.cpp
@@ -64,12 +64,12 @@ Element* LiveNodeList::item(unsigned offset) const
     return m_collectionIndexCache.nodeAt(*this, offset);
 }
 
-Element* LiveNodeList::traverseToFirstElement() const
+Element* LiveNodeList::traverseToFirst() const
 {
     return ElementTraversal::firstWithin(rootNode(), IsMatch(*this));
 }
 
-Element* LiveNodeList::traverseToLastElement() const
+Element* LiveNodeList::traverseToLast() const
 {
     return ElementTraversal::lastWithin(rootNode(), IsMatch(*this));
 }