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

webkit/fileapi/file_system_test_helper.cc

Index: webkit/fileapi/file_system_test_helper.cc
diff --git a/webkit/fileapi/file_system_test_helper.cc b/webkit/fileapi/file_system_test_helper.cc
index dd5bfa45abfad4bda6cad02eb31ab967931362e6..85edf5dba8e3d04432ad6d184547c9e3c0556176 100644
--- a/webkit/fileapi/file_system_test_helper.cc
+++ b/webkit/fileapi/file_system_test_helper.cc
@@ -57,13 +57,12 @@ FileSystemTestOriginHelper::~FileSystemTestOriginHelper() {
 }
 
 void FileSystemTestOriginHelper::SetUp(
-    const FilePath& base_dir, FileSystemFileUtil* file_util) {
+    const FilePath& base_dir, FileUtil* file_util) {
   SetUp(base_dir, false, false, NULL, file_util);
 }
 
 void FileSystemTestOriginHelper::SetUp(
-    FileSystemContext* file_system_context,
-    FileSystemFileUtil* file_util) {
+    FileSystemContext* file_system_context, FileUtil* file_util) {
   DCHECK(file_system_context->path_manager());
   DCHECK(file_system_context->path_manager()->sandbox_provider());
 
@@ -71,7 +70,7 @@ void FileSystemTestOriginHelper::SetUp(
   file_system_context_ = file_system_context;
   if (!file_util_)
     file_util_ = file_system_context->path_manager()->sandbox_provider()->
-        GetFileSystemFileUtil();
+        GetFileUtil();
   DCHECK(file_util_);
 
   // Prepare the origin's root directory.
@@ -90,7 +89,7 @@ void FileSystemTestOriginHelper::SetUp(
     bool incognito_mode,
     bool unlimited_quota,
     quota::QuotaManagerProxy* quota_manager_proxy,
-    FileSystemFileUtil* file_util) {
+    FileUtil* file_util) {
   file_util_ = file_util;
   DCHECK(file_util_);
   file_system_context_ = new FileSystemContext(