WTF/std normalization: replace WTF::Vector::first() with ::front()

third_party/WebKit/Source/core/html/HTMLSlotElement.h

 /*
  * Copyright (C) 2015 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 35 matching lines @@
 
   const HeapVector<Member<Node>>& assignedNodes();
   const HeapVector<Member<Node>>& getDistributedNodes();
   const HeapVector<Member<Node>> getDistributedNodesForBinding();
   const HeapVector<Member<Node>> assignedNodesForBinding(
       const AssignedNodesOptions&);
 
   Node* firstDistributedNode() const {
     DCHECK(supportsDistribution());
     return m_distributedNodes.isEmpty() ? nullptr
-                                        : m_distributedNodes.first().get();
+                                        : m_distributedNodes.front().get();
   }
   Node* lastDistributedNode() const {
     DCHECK(supportsDistribution());
     return m_distributedNodes.isEmpty() ? nullptr
                                         : m_distributedNodes.back().get();
   }
 
   Node* distributedNodeNextTo(const Node&) const;
   Node* distributedNodePreviousTo(const Node&) const;
 
@@ skipping 47 matching lines @@
   HeapVector<Member<Node>> m_assignedNodes;
   HeapVector<Member<Node>> m_distributedNodes;
   HeapVector<Member<Node>> m_oldDistributedNodes;
   HeapHashMap<Member<const Node>, size_t> m_distributedIndices;
   bool m_slotchangeEventEnqueued = false;
 };
 
 }  // namespace blink
 
 #endif  // HTMLSlotElement_h