Avoid WTF::Vector::at() and operator[] in core/dom.

third_party/WebKit/Source/core/dom/SpaceSplitString.h

 /*
  * Copyright (C) 2007, 2008, 2010, 2011, 2012 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 49 matching lines @@
 
  private:
   class Data : public RefCounted<Data> {
    public:
     static PassRefPtr<Data> create(const AtomicString&);
     static PassRefPtr<Data> createUnique(const Data&);
 
     ~Data();
 
     bool contains(const AtomicString& string) {
-      size_t size = m_vector.size();
-      for (size_t i = 0; i < size; ++i) {
-        if (m_vector[i] == string)
+      for (const auto& item : m_vector) {
+        if (item == string)
           return true;
       }
       return false;
     }
 
     bool containsAll(Data&);
 
     void add(const AtomicString&);
     void remove(unsigned index);
 
@@ skipping 20 matching lines @@
     if (m_data && !m_data->isUnique())
       m_data = Data::createUnique(*m_data);
   }
 
   RefPtr<Data> m_data;
 };
 
 }  // namespace blink
 
 #endif  // SpaceSplitString_h