Is the correct fix to remove the part that prepends "Casting", or to change the route description here: https://cs.chromium.org/chromium/src/chrome/browser/resources/media_router/extension/src/mirror_services/mirror_activity.js?type=cs&q=%22Casting+tab%22&sq=package:chromium&g=0&l=104

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/9c97d59ac93b0e4e67809ba4cefa5603b8f78616

commit 9c97d59ac93b0e4e67809ba4cefa5603b8f78616
Author: mark a. foltz <mfoltz@chromium.org>
Date: Fri Jul 13 18:06:25 2018

[Media Router] Update ChromeOS system tray UI.

Media route descriptions are not intended to be used as part of a larger string.
This change brings the ChromeOS system tray strings in line with the current set
of media route descriptions and avoids strings that start with "Casting Casting".

Before/after screenshots:

https://drive.google.com/drive/folders/1yPo-Gx_a2D6OGAQM715DU7vthKl2fH1o?usp=sharing

Bug:  837394 
Change-Id: Iac4a443a361ad3fd457059f6b4588ab2edc4ecda
Reviewed-on: https://chromium-review.googlesource.com/1128330
Reviewed-by: Dan Erat <derat@chromium.org>
Reviewed-by: Takumi Fujimoto <takumif@chromium.org>
Reviewed-by: Sadrul Chowdhury <sadrul@chromium.org>
Commit-Queue: mark a. foltz <mfoltz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#574976}
[modify] https://crrev.com/9c97d59ac93b0e4e67809ba4cefa5603b8f78616/ash/ash_strings.grd
[modify] https://crrev.com/9c97d59ac93b0e4e67809ba4cefa5603b8f78616/ash/system/cast/cast_notification_controller.cc
[modify] https://crrev.com/9c97d59ac93b0e4e67809ba4cefa5603b8f78616/chrome/browser/ui/ash/cast_config_client_media_router.cc