Adding some description:

The active cast session not shown in CrOS system tray first time after login.

Repro steps:
1. sign out and sign back in to the machine
2. Cast entire desktop using cast icon in toolbar.
3. wait 30 seconds.

Actual: no cast icon is displayed in the toolbar and menu shows device list without a stop button
Expected: Cast icon displayed in toolbar immediately after session starts and menu shows active session with stop button 

3. open and close taskbar menu

Now the cast icon is displayed and when the taskbar menu is re-opened, a stop casting button appears.

*Repros every time

This will be fixed once https://codereview.chromium.org/2424183002/ lands.

It looks like that patch just landed :)

The patch in comment 6 ended up getting split up; the code that fixes this bug is now inside of this patch: https://codereview.chromium.org/2466043002/.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/e8ea94d6917ade3afc5f7c3164369ef15c3e76c9

commit e8ea94d6917ade3afc5f7c3164369ef15c3e76c9
Author: jdufault <jdufault@chromium.org>
Date: Wed Nov 16 19:57:24 2016

Cleanup TrayCast with media-router only support in mind.

This allows the TrayCast instance to immediately connect to the CastConfigDelegate, which allows TrayCast to fetch cast data before the tray pops up the first time.

This also allows TrayCast to properly support DIAL casts. A DIAL cast is when the Chromecast / sink stream directly from another source, ie, YouTube.

BUG= 653313 

Review-Url: https://codereview.chromium.org/2466043002
Cr-Commit-Position: refs/heads/master@{#432603}

[modify] https://crrev.com/e8ea94d6917ade3afc5f7c3164369ef15c3e76c9/ash/common/cast_config_delegate.h
[modify] https://crrev.com/e8ea94d6917ade3afc5f7c3164369ef15c3e76c9/ash/common/system/chromeos/cast/tray_cast.cc
[modify] https://crrev.com/e8ea94d6917ade3afc5f7c3164369ef15c3e76c9/ash/common/system/chromeos/cast/tray_cast.h
[modify] https://crrev.com/e8ea94d6917ade3afc5f7c3164369ef15c3e76c9/ash/test/tray_cast_test_api.cc
[modify] https://crrev.com/e8ea94d6917ade3afc5f7c3164369ef15c3e76c9/chrome/browser/ui/ash/cast_config_delegate_media_router.cc
[modify] https://crrev.com/e8ea94d6917ade3afc5f7c3164369ef15c3e76c9/chrome/browser/ui/ash/cast_config_delegate_media_router.h