Force MediaSource reset when there are EME config changes
Created by: epiclabsDASH
Workaround to #2795 (closed). Trying to reuse a MediaSource across two periods, in which one of them defines a DRM system and the other one not, makes Chrome to crash.
This PR avoid the crash although makes period transition in above cases to be not seamless. I will create a new ticket to investigate if this is a limitation of the browser. In that case I will create a ticket in Chromium project.