Add explicit base namespace to string16 users.

chrome/common/extensions/api/managed_mode_private/managed_mode_handler.h

 // Copyright (c) 2013 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_COMMON_EXTENSIONS_API_MANAGED_MODE_PRIVATE_MANAGED_MODE_HANDLER_H_
 #define CHROME_COMMON_EXTENSIONS_API_MANAGED_MODE_PRIVATE_MANAGED_MODE_HANDLER_H_
 
 #include <string>
 
 #include "base/files/file_path.h"
@@ skipping 15 matching lines @@
   // A file containing a list of sites for Managed Mode.
   base::FilePath site_list;
 };
 
 // Parses the "content_pack" manifest key for Managed Mode.
 class ManagedModeHandler : public ManifestHandler {
  public:
   ManagedModeHandler();
   virtual ~ManagedModeHandler();
 
-  virtual bool Parse(Extension* extension, string16* error) OVERRIDE;
+  virtual bool Parse(Extension* extension, base::string16* error) OVERRIDE;
  private:
   virtual const std::vector<std::string> Keys() const OVERRIDE;
 
   bool LoadSites(ManagedModeInfo* info,
                  const base::DictionaryValue* content_pack_value,
-                 string16* error);
+                 base::string16* error);
   bool LoadConfigurations(ManagedModeInfo* info,
                           const base::DictionaryValue* content_pack_value,
-                          string16* error);
+                          base::string16* error);
 
   DISALLOW_COPY_AND_ASSIGN(ManagedModeHandler);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_COMMON_EXTENSIONS_API_MANAGED_MODE_PRIVATE_MANAGED_MODE_HANDLER_H_