Move UserScript and related into extensions namespace

chrome/browser/extensions/convert_user_script.h

Index: chrome/browser/extensions/convert_user_script.h
diff --git a/chrome/browser/extensions/convert_user_script.h b/chrome/browser/extensions/convert_user_script.h
index 480b6aed456edb8ac96870d3f6c1b3852a2806c4..fa34c2d308c431165ae0135d8ed51269eefc6ef7 100644
--- a/chrome/browser/extensions/convert_user_script.h
+++ b/chrome/browser/extensions/convert_user_script.h
@@ -15,7 +15,6 @@ class GURL;
 
 namespace extensions {
 class Extension;
-}
 
 // Wraps the specified user script in an extension. The extension is created
 // unpacked in the system temp dir. Returns a valid extension that the caller
@@ -27,4 +26,6 @@ class Extension;
 scoped_refptr<extensions::Extension> ConvertUserScriptToExtension(
     const FilePath& user_script, const GURL& original_url, string16* error);
 
+}  // namespace extensions
+
 #endif  // CHROME_BROWSER_EXTENSIONS_CONVERT_USER_SCRIPT_H_