This prevents user from accidentally specifying a directory that contains files that the user wants to keep. BUG=webrtc:7608 NOTRY=True Review-Url: https://codereview.webrtc.org/2876803002 Cr-Commit-Position: refs/heads/master@{#18096}
BUG=webrtc:7608 Review-Url: https://codereview.webrtc.org/2858043006 Cr-Commit-Position: refs/heads/master@{#18063}