The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/a0754d77aa3aaf5b7adab6f718e988ea8b88c9e9

commit a0754d77aa3aaf5b7adab6f718e988ea8b88c9e9
Author: Becca Hughes <beccahughes@chromium.org>
Date: Tue Oct 09 00:33:40 2018

[Audio Focus] Replace request_id with UnguessableToken

We should replace request_id with base::UnguessableToken.

BUG= 892773 

Change-Id: Iee8adfea65f16c2ec6d893a2ba55bc271d54a98d
Reviewed-on: https://chromium-review.googlesource.com/c/1265938
Reviewed-by: Dan Sanders <sandersd@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Commit-Queue: Becca Hughes <beccahughes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#597753}
[modify] https://crrev.com/a0754d77aa3aaf5b7adab6f718e988ea8b88c9e9/content/browser/media/media_internals.cc
[modify] https://crrev.com/a0754d77aa3aaf5b7adab6f718e988ea8b88c9e9/content/browser/media/media_internals.h
[modify] https://crrev.com/a0754d77aa3aaf5b7adab6f718e988ea8b88c9e9/content/browser/media/media_internals_unittest.cc
[modify] https://crrev.com/a0754d77aa3aaf5b7adab6f718e988ea8b88c9e9/services/media_session/audio_focus_manager.cc
[modify] https://crrev.com/a0754d77aa3aaf5b7adab6f718e988ea8b88c9e9/services/media_session/audio_focus_manager.h
[modify] https://crrev.com/a0754d77aa3aaf5b7adab6f718e988ea8b88c9e9/services/media_session/audio_focus_manager_unittest.cc
[modify] https://crrev.com/a0754d77aa3aaf5b7adab6f718e988ea8b88c9e9/services/media_session/public/mojom/audio_focus.mojom