Version: 55.0.2868.0
OS: Android NDE63N
Device: Sailfish

What steps will reproduce the problem?
(1) Download an MP4 file (say).
(2) Go to the Chrome Downloads menu.
(3) Tap on the MP4 file to start playing it back.

In the media player UI controls, there is a download button shown -- even though we're already playing back a downloaded media file.

This is pretty confusing and should be easy to fix; e.g., don't show the download button when it's a file:// URL.