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

third_party/WebKit/Source/core/html/parser/HTMLTreeBuilder.cpp

 /*
  * Copyright (C) 2010 Google, Inc. All Rights Reserved.
  * Copyright (C) 2011, 2014 Apple 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 462 matching lines @@
 
 template <std::unique_ptr<const QualifiedName* []> getAttrs(), unsigned length>
 static void adjustAttributes(AtomicHTMLToken* token) {
   static PrefixedNameToQualifiedNameMap* caseMap = 0;
   if (!caseMap) {
     caseMap = new PrefixedNameToQualifiedNameMap;
     std::unique_ptr<const QualifiedName* []> attrs = getAttrs();
     mapLoweredLocalNameToName(caseMap, attrs.get(), length);
   }
 
-  for (unsigned i = 0; i < token->attributes().size(); ++i) {
-    Attribute& tokenAttribute = token->attributes().at(i);
+  for (auto& tokenAttribute : token->attributes()) {
     const QualifiedName& casedName = caseMap->get(tokenAttribute.localName());
     if (!casedName.localName().isNull())
       tokenAttribute.parserSetName(casedName);
   }
 }
 
 static void adjustSVGAttributes(AtomicHTMLToken* token) {
   adjustAttributes<SVGNames::getSVGAttrs, SVGNames::SVGAttrsCount>(token);
 }
 
@@ skipping 2260 matching lines @@
     DEFINE_STRINGIFY(AfterFramesetMode)
     DEFINE_STRINGIFY(AfterAfterBodyMode)
     DEFINE_STRINGIFY(AfterAfterFramesetMode)
 #undef DEFINE_STRINGIFY
   }
   return "<unknown>";
 }
 #endif
 
 }  // namespace blink