Media Controls: Remove 'modern' from the code

This CL removes the word 'modern' from the rest of the media controls
code.

Bug: 884215
Change-Id: I502c6717a8ce15d667e3fce0bd1726038aca2f76
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1677104
Reviewed-by: Becca Hughes <beccahughes@chromium.org>
Commit-Queue: Tommy Steimel <steimel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#672247}
3 files changed