Move StringPiece into the base namespace. It is colliding

chrome/renderer/user_script_slave.h

 // Copyright (c) 2009 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_BROWSER_EXTENSIONS_USER_SCRIPT_SLAVE_H_
 #define CHROME_BROWSER_EXTENSIONS_USER_SCRIPT_SLAVE_H_
 
 #include <map>
 #include <vector>
 
@@ skipping 22 matching lines @@
 
  private:
   // Shared memory containing raw script data.
   scoped_ptr<base::SharedMemory> shared_memory_;
 
   // Parsed script data.
   std::vector<UserScript*> scripts_;
   STLElementDeleter<std::vector<UserScript*> > script_deleter_;
 
   // Greasemonkey API source that is injected with the scripts.
-  StringPiece api_js_;
+  base::StringPiece api_js_;
 
   // The line number of the first line of the user script among all of the
   // injected javascript.  This is used to make reported errors correspond with
   // the proper line in the user script.
   int user_script_start_line_;
 
   DISALLOW_COPY_AND_ASSIGN(UserScriptSlave);
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_USER_SCRIPT_SLAVE_H_