The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/18f7750476c61d8b5aeea694f87826e38ec022fd

commit 18f7750476c61d8b5aeea694f87826e38ec022fd
Author: Takumi Fujimoto <takumif@chromium.org>
Date: Thu Jun 14 03:23:30 2018

[Harmony Cast Dialog] Implement the no devices view

This is the view that is shown when there are no devices found.
For the first three seconds, it will show a throbber. After that, it
will show a help icon that links to a help center article.

Whenever the dialog receives a model update containing sinks, the "no
devices" view is replaced with the sink list view.

Video:
https://drive.google.com/open?id=18zr2x3B30HsRc0j9hYry8_dZWXAlW5e_

Bug:  846164 
Change-Id: I203197b5300c604a062deb303c18d5c98631c761
Reviewed-on: https://chromium-review.googlesource.com/1089580
Commit-Queue: Takumi Fujimoto <takumif@chromium.org>
Reviewed-by: Bret Sepulveda <bsep@chromium.org>
Reviewed-by: mark a. foltz <mfoltz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#567113}
[modify] https://crrev.com/18f7750476c61d8b5aeea694f87826e38ec022fd/chrome/app/media_router_strings.grdp
[modify] https://crrev.com/18f7750476c61d8b5aeea694f87826e38ec022fd/chrome/browser/ui/BUILD.gn
[add] https://crrev.com/18f7750476c61d8b5aeea694f87826e38ec022fd/chrome/browser/ui/views/media_router/cast_dialog_no_sinks_view.cc
[add] https://crrev.com/18f7750476c61d8b5aeea694f87826e38ec022fd/chrome/browser/ui/views/media_router/cast_dialog_no_sinks_view.h
[add] https://crrev.com/18f7750476c61d8b5aeea694f87826e38ec022fd/chrome/browser/ui/views/media_router/cast_dialog_no_sinks_view_unittest.cc
[modify] https://crrev.com/18f7750476c61d8b5aeea694f87826e38ec022fd/chrome/browser/ui/views/media_router/cast_dialog_sink_button.cc
[modify] https://crrev.com/18f7750476c61d8b5aeea694f87826e38ec022fd/chrome/browser/ui/views/media_router/cast_dialog_sink_button.h
[modify] https://crrev.com/18f7750476c61d8b5aeea694f87826e38ec022fd/chrome/browser/ui/views/media_router/cast_dialog_view.cc
[modify] https://crrev.com/18f7750476c61d8b5aeea694f87826e38ec022fd/chrome/browser/ui/views/media_router/cast_dialog_view.h
[modify] https://crrev.com/18f7750476c61d8b5aeea694f87826e38ec022fd/chrome/browser/ui/views/media_router/cast_dialog_view_unittest.cc
[modify] https://crrev.com/18f7750476c61d8b5aeea694f87826e38ec022fd/chrome/browser/ui/views/media_router/media_router_dialog_controller_views.cc
[modify] https://crrev.com/18f7750476c61d8b5aeea694f87826e38ec022fd/chrome/common/url_constants.cc
[modify] https://crrev.com/18f7750476c61d8b5aeea694f87826e38ec022fd/chrome/common/url_constants.h
[modify] https://crrev.com/18f7750476c61d8b5aeea694f87826e38ec022fd/chrome/test/BUILD.gn