Update from https://crrev.com/306655

net/base/file_stream_context.h

 // Copyright (c) 2012 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.
 
 // This file defines FileStream::Context class.
 // The general design of FileStream is as follows: file_stream.h defines
 // FileStream class which basically is just an "wrapper" not containing any
 // specific implementation details. It re-routes all its method calls to
 // the instance of FileStream::Context (FileStream holds a scoped_ptr to
 // FileStream::Context instance). Context was extracted into a different class
@@ skipping 82 matching lines @@
 
   void Seek(base::File::Whence whence,
             int64 offset,
             const Int64CompletionCallback& callback);
 
   void Flush(const CompletionCallback& callback);
 
  private:
   struct IOResult {
     IOResult();
-    IOResult(int64 result, int os_error);
-    static IOResult FromOSError(int64 os_error);
+    IOResult(int64 result, logging::SystemErrorCode os_error);
+    static IOResult FromOSError(logging::SystemErrorCode os_error);
 
     int64 result;
-    int os_error;  // Set only when result < 0.
+    logging::SystemErrorCode os_error;  // Set only when result < 0.
   };
 
   struct OpenResult {
     MOVE_ONLY_TYPE_FOR_CPP_03(OpenResult, RValue)
    public:
     OpenResult();
     OpenResult(base::File file, IOResult error_code);
     // C++03 move emulation of this type.
     OpenResult(RValue other);
     OpenResult& operator=(RValue other);
@@ skipping 62 matching lines @@
   CompletionCallback callback_;
   scoped_refptr<IOBuffer> in_flight_buf_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(Context);
 };
 
 }  // namespace net
 
 #endif  // NET_BASE_FILE_STREAM_CONTEXT_H_