Use base namespace for string16 in chrome/renderer.

chrome/renderer/spellchecker/custom_dictionary_engine.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_RENDERER_SPELLCHECKER_CUSTOM_DICTIONARY_ENGINE_H_
 #define CHROME_RENDERER_SPELLCHECKER_CUSTOM_DICTIONARY_ENGINE_H_
 
 #include <set>
 #include <string>
 #include <vector>
 
 #include "base/strings/string16.h"
 
 // Custom spellcheck dictionary. Words in this dictionary are always correctly
 // spelled. Words that are not in this dictionary may or may not be correctly
 // spelled.
 class CustomDictionaryEngine {
  public:
   CustomDictionaryEngine();
   ~CustomDictionaryEngine();
 
   // Initialize the custom dictionary engine.
   void Init(const std::set<std::string>& words);
 
   // Spellcheck |text|. Assumes that another spelling engine has set
   // |misspelling_start| and |misspelling_len| to indicate a misspelling.
   // Returns true if there are no misspellings, otherwise returns false.
-  bool SpellCheckWord(const string16& text,
+  bool SpellCheckWord(const base::string16& text,
                       int misspelling_start,
                       int misspelling_len);
 
   // Update custom dictionary words.
   void OnCustomDictionaryChanged(
       const std::vector<std::string>& words_added,
       const std::vector<std::string>& words_removed);
 
  private:
   // Correctly spelled words.
-  std::set<string16> dictionary_;
+  std::set<base::string16> dictionary_;
 
   DISALLOW_COPY_AND_ASSIGN(CustomDictionaryEngine);
 };
 
 #endif  // CHROME_RENDERER_SPELLCHECKER_CUSTOM_DICTIONARY_ENGINE_H_