Replace base::File wrapping with typemapping.

components/filesystem/directory_impl.h

 // 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.
 
 #ifndef COMPONENTS_FILESYSTEM_DIRECTORY_IMPL_H_
 #define COMPONENTS_FILESYSTEM_DIRECTORY_IMPL_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 46 matching lines @@
   void StatFile(const std::string& path,
                 const StatFileCallback& callback) override;
   void Clone(mojom::DirectoryRequest directory) override;
   void ReadEntireFile(const std::string& path,
                       const ReadEntireFileCallback& callback) override;
   void WriteFile(const std::string& path,
                  const std::vector<uint8_t>& data,
                  const WriteFileCallback& callback) override;
 
  private:
-  mojo::ScopedHandle OpenFileHandleImpl(const std::string& raw_path,
-                                        uint32_t open_flags,
-                                        mojom::FileError* error);
+  base::File OpenFileHandleImpl(const std::string& raw_path,
+                                uint32_t open_flags);
 
   base::FilePath directory_path_;
   scoped_refptr<SharedTempDir> temp_dir_;
   scoped_refptr<LockTable> lock_table_;
 
   DISALLOW_COPY_AND_ASSIGN(DirectoryImpl);
 };
 
 }  // namespace filesystem
 
 #endif  // COMPONENTS_FILESYSTEM_DIRECTORY_IMPL_H_