Fix crash in DirectoryImpl::Flush()

components/filesystem/directory_impl.cc

 // Copyright 2015 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.
 
 #include "components/filesystem/directory_impl.h"
 
 #include <utility>
 
 #include "base/files/file.h"
 #include "base/files/file_enumerator.h"
@@ skipping 206 matching lines @@
   mojom::FileError error = ValidatePath(raw_path, directory_path_, &path);
   if (error != mojom::FileError::OK) {
     callback.Run(error, false);
     return;
   }
 
   callback.Run(mojom::FileError::OK, base::PathIsWritable(path));
 }
 
 void DirectoryImpl::Flush(const FlushCallback& callback) {
-  base::File file(directory_path_, base::File::FLAG_READ);
+  base::File file(directory_path_,
+                  base::File::FLAG_OPEN | base::File::FLAG_READ);
   if (!file.IsValid()) {
     callback.Run(GetError(file));
     return;
   }
 
   if (!file.Flush()) {
     callback.Run(mojom::FileError::FAILED);
     return;
   }
 
@@ skipping 108 matching lines @@
     // We must not return directories as files. In the file abstraction, we
     // can fetch raw file descriptors over mojo pipes, and passing a file
     // descriptor to a directory is a sandbox escape on Windows.
     return base::File(base::File::FILE_ERROR_NOT_A_FILE);
   }
 
   return base::File(path, open_flags);
 }
 
 }  // namespace filesystem