[Refactor] to rename and re-layer the file_util stack layers.

webkit/fileapi/quota_file_util.h

Index: webkit/fileapi/quota_file_util.h
diff --git a/webkit/fileapi/quota_file_util.h b/webkit/fileapi/quota_file_util.h
index 991497b7dfe52b799971fac9bdfe9ed6b824a9a2..25be5f3619848e55484a7720d53c676d4dd87aa5 100644
--- a/webkit/fileapi/quota_file_util.h
+++ b/webkit/fileapi/quota_file_util.h
@@ -25,28 +25,24 @@ class QuotaFileUtil : public FileSystemFileUtil {
   explicit QuotaFileUtil(FileSystemFileUtil* underlying_file_util);
   virtual ~QuotaFileUtil();
 
-  // Creates a QuotaFileUtil instance with an underlying FileSystemFileUtil
+  // Creates a QuotaFileUtil instance with an underlying NativeFileUtil
   // instance.
   static QuotaFileUtil* CreateDefault();
 
+  virtual base::PlatformFileError Truncate(
+      FileSystemOperationContext* fs_context,
+      const FilePath& path,
+      int64 length) OVERRIDE;
   virtual base::PlatformFileError CopyOrMoveFile(
       FileSystemOperationContext* fs_context,
       const FilePath& src_file_path,
       const FilePath& dest_file_path,
       bool copy) OVERRIDE;
-
   virtual base::PlatformFileError DeleteFile(
       FileSystemOperationContext* fs_context,
       const FilePath& file_path) OVERRIDE;
 
-  virtual base::PlatformFileError Truncate(
-      FileSystemOperationContext* fs_context,
-      const FilePath& path,
-      int64 length) OVERRIDE;
-
  private:
-  scoped_ptr<FileSystemFileUtil> underlying_file_util_;
-
   DISALLOW_COPY_AND_ASSIGN(QuotaFileUtil);
 };