[fsp] [recommit #2] Add an initial AsyncFileUtil.

chrome/browser/chromeos/fileapi/file_system_backend.h

Index: chrome/browser/chromeos/fileapi/file_system_backend.h
diff --git a/chrome/browser/chromeos/fileapi/file_system_backend.h b/chrome/browser/chromeos/fileapi/file_system_backend.h
index df7bff15868400ef6a10683023b08d64f84cec1e..409b36d97e2822701b3616e2372fb6f4da222a3d 100644
--- a/chrome/browser/chromeos/fileapi/file_system_backend.h
+++ b/chrome/browser/chromeos/fileapi/file_system_backend.h
@@ -70,9 +70,11 @@ class FileSystemBackend : public fileapi::ExternalFileSystemBackend {
   // FileSystemBackend will take an ownership of a |mount_points|
   // reference. On the other hand, |system_mount_points| will be kept as a raw
   // pointer and it should outlive FileSystemBackend instance.
-  // The ownership of |drive_delegate| is also taken.
+  // The ownerships of |drive_delegate| and |file_system_provider_delegate| are
+  // also taken.
   FileSystemBackend(
       FileSystemBackendDelegate* drive_delegate,
+      FileSystemBackendDelegate* file_system_provider_delegate,
       scoped_refptr<quota::SpecialStoragePolicy> special_storage_policy,
       scoped_refptr<fileapi::ExternalMountPoints> mount_points,
       fileapi::ExternalMountPoints* system_mount_points);
@@ -135,9 +137,12 @@ class FileSystemBackend : public fileapi::ExternalFileSystemBackend {
   scoped_ptr<FileAccessPermissions> file_access_permissions_;
   scoped_ptr<fileapi::AsyncFileUtil> local_file_util_;
 
-  // The Delegate instance for the drive file system related operation.
+  // The delegate instance for the drive file system related operations.
   scoped_ptr<FileSystemBackendDelegate> drive_delegate_;
 
+  // The delegate instance for the provided file system related operations.
+  scoped_ptr<FileSystemBackendDelegate> file_system_provider_delegate_;
+
   // Mount points specific to the owning context (i.e. per-profile mount
   // points).
   //