Reason for revert:
Fails to compile successfully.
Original issue's description:
> Reduce dependencies on rtc::FileSystem in FileRotatingStream tests.
>
> Use webrtc::test::OutputPath instead of Filesystem::GetAppTempFolder.
> Added functions RemoveFile and RemoveDir in the webrtc::test namespace,
> to replace use of Filesystem::DeleteFolderAndContents.
>
> This makes Filesystem::DeleteFolderAndContents unused, to be deleted
> together with related code in a followup cl.
>
> BUG=webrtc:7345
>
> Review-Url: https://codereview.webrtc.org/2872283002
> Cr-Commit-Position: refs/heads/master@{#18173}
> Committed: dd7b5f32b5
TBR=pthatcher@webrtc.org,kjellander@webrtc.org,tommi@webrtc.org,nisse@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=webrtc:7345
Review-Url: https://codereview.webrtc.org/2885393002
Cr-Commit-Position: refs/heads/master@{#18180}
Name: WebRTC URL: http://www.webrtc.org Version: 90 License: BSD License File: LICENSE Description: WebRTC provides real time voice and video processing functionality to enable the implementation of PeerConnection/MediaStream. Third party code used in this project is described in the file LICENSE_THIRD_PARTY.