Add explicit base namespace to string16 users.

chrome/common/extensions/api/commands/commands_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_COMMANDS_COMMANDS_HANDLER_H_
 #define CHROME_COMMON_EXTENSIONS_API_COMMANDS_COMMANDS_HANDLER_H_
 
 #include <string>
 
 #include "base/memory/scoped_ptr.h"
@@ skipping 22 matching lines @@
   static const Command* GetScriptBadgeCommand(const Extension* extension);
   static const CommandMap* GetNamedCommands(const Extension* extension);
 };
 
 // Parses the "commands" manifest key.
 class CommandsHandler : public ManifestHandler {
  public:
   CommandsHandler();
   virtual ~CommandsHandler();
 
-  virtual bool Parse(Extension* extension, string16* error) OVERRIDE;
+  virtual bool Parse(Extension* extension, base::string16* error) OVERRIDE;
   virtual bool AlwaysParseForType(Manifest::Type type) const OVERRIDE;
 
  private:
   // If the extension defines a browser action, but no command for it, then
   // we synthesize a generic one, so the user can configure a shortcut for it.
   // No keyboard shortcut will be assigned to it, until the user selects one.
   void MaybeSetBrowserActionDefault(const Extension* extension,
                                     CommandsInfo* info);
 
   virtual const std::vector<std::string> Keys() const OVERRIDE;
 
   DISALLOW_COPY_AND_ASSIGN(CommandsHandler);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_COMMON_EXTENSIONS_API_COMMANDS_COMMANDS_HANDLER_H_