Move StringPiece into the base namespace. It is colliding

chrome/common/extensions/user_script.h

 // Copyright 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_COMMON_EXTENSIONS_USER_SCRIPT_H_
 #define CHROME_COMMON_EXTENSIONS_USER_SCRIPT_H_
 
 #include <vector>
 #include <string>
 
@@ skipping 30 matching lines @@
     File() {}
 
     const FilePath& path() const { return path_; }
     void set_path(const FilePath& path) { path_ = path; }
 
     const GURL& url() const { return url_; }
     void set_url(const GURL& url) { url_ = url; }
 
     // If external_content_ is set returns it as content otherwise it returns
     // content_
-    const StringPiece GetContent() const {
+    const base::StringPiece GetContent() const {
       if (external_content_.data())
         return external_content_;
       else
         return content_;
     }
-    void set_external_content(const StringPiece& content) {
+    void set_external_content(const base::StringPiece& content) {
       external_content_ = content;
     }
-    const void set_content(const StringPiece& content) {
+    const void set_content(const base::StringPiece& content) {
       content_.assign(content.begin(), content.end());
     }
 
     // Serialization support. The content and path_ member will not be
     // serialized!
     void Pickle(::Pickle* pickle) const;
     void Unpickle(const ::Pickle& pickle, void** iter);
 
    private:
     // Where is the script file lives on the disk.
     FilePath path_;
 
     // The url to this scipt file.
     GURL url_;
 
     // The script content. It can be set to either loaded_content_ or
     // externally allocated string.
-    StringPiece external_content_;
+    base::StringPiece external_content_;
 
     // Set when the content is loaded by LoadContent
     std::string content_;
   };
 
   typedef std::vector<File> FileList;
 
   // Constructor. Default the run location to document end, which is like
   // Greasemonkey and probably more useful for typical scripts.
   UserScript() : run_location_(DOCUMENT_END) {}
@@ skipping 61 matching lines @@
   FileList css_scripts_;
 
   // The ID of the extension this script is a part of, if any. Can be empty if
   // the script is a "standlone" user script.
   std::string extension_id_;
 };
 
 typedef std::vector<UserScript> UserScriptList;
 
 #endif  // CHROME_COMMON_EXTENSIONS_USER_SCRIPT_H_