GitLab

This CL rename the enum class to FileErrorCode and move it out of the
namespace file_error.

Change-Id: I39ee10e35bbdcf0b3b0efdda159e21b255e477b1
Reviewed-on: https://chromium-review.googlesource.com/c/1328628Reviewed-by: Victor Costan <pwnall@chromium.org>
Reviewed-by: Adam Rice <ricea@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Commit-Queue: Victor Costan <pwnall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#609619}