Add base:: to string16 in chrome_frame/.

chrome_frame/test_utils.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_FRAME_TEST_UTILS_H_
 #define CHROME_FRAME_TEST_UTILS_H_
 
 #include <string>
 
 #include <atlbase.h>
@@ skipping 53 matching lines @@
 
  private:
   enum RegistrationOperation {
     REGISTER,
     UNREGISTER,
   };
 
   // The string "--call-registration-entrypoint".
   static const wchar_t kCallRegistrationEntrypointSwitch[];
 
-  static void DoRegistration(const string16& path,
+  static void DoRegistration(const base::string16& path,
                              RegistrationType registration_type,
                              RegistrationOperation registration_operation);
 
   // Contains the path of the most recently registered Chrome Frame DLL.
   std::wstring new_chrome_frame_dll_path_;
 
   // Contains the path of the Chrome Frame DLL to be registered at destruction.
   std::wstring original_dll_path_;
 
   // Indicates whether per user or per machine registration is needed.
@@ skipping 40 matching lines @@
   }
 
   T* owner_;
   Method method_;
 };
 
 // If the workstation is locked and cannot receive user input.
 bool IsWorkstationLocked();
 
 #endif  // CHROME_FRAME_TEST_UTILS_H_