GitLab

This CL makes sure audio and video tracks information are reflected in
HTMLMediaElement audioTracks and videoTracks when source is a MediaStream.

  Platform features" flag enabled.

Test: https://glowing-juvenile-bear.glitch.me/ with "Experimental Web
Bug: 894556
Change-Id: Iceac66b1f142d5c28eeaaffefd621c095e65ecda
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2518856Reviewed-by: Guido Urdaneta <guidou@chromium.org>
Commit-Queue: François Beaufort <beaufort.francois@gmail.com>
Cr-Commit-Position: refs/heads/master@{#824360}