Wire up tab muting for audio service.

When using the audio service for audio streams,
WebContentsImpl::SetAudioMuted must mute the streams by calling
the audio service, rather than using the (currently used)
WebContentsAudioMuter. This CL updates WebContentsImpl to
communicate with the audio service when
features::kAudioServiceAudioStreams is set, and also removes an old
hack used for muting when the audio service is in-process.

Bug: 824019
Change-Id: Idbe29f0edc6fd0f68287ad6254021969916a38d6
Reviewed-on: https://chromium-review.googlesource.com/1059953
Commit-Queue: Max Morin <[email protected]>
Reviewed-by: Olga Sharonova <[email protected]>
Reviewed-by: Kinuko Yasuda <[email protected]>
Cr-Commit-Position: refs/heads/master@{#559007}
2 files changed