GitLab

This reverts commit 59692b72.

Reason for revert:

Findit (https://goo.gl/kROfz5) identified CL at revision 553433 as the
culprit for failures in the build cycles as shown on:
https://findit-for-me.appspot.com/waterfall/culprit?key=ag9zfmZpbmRpdC1mb3ItbWVyRAsSDVdmU3VzcGVjdGVkQ0wiMWNocm9taXVtLzU5NjkyYjcyYmMzNGNiYmM5ZGM3ZmY0NDE0ZjNjODQ2YTU4NzMyOWYM

Sample Failed Build: https://ci.chromium.org/buildbot/chromium.memory/Linux%20Chromium%20OS%20ASan%20LSan%20Tests%20%281%29/27188

Sample Failed Step: mus_ash_unittests

Original change's description:
> Observe ClockModel directly from DateView/TimeView
> 
> This CL changes DateView and TimeView to directly observe ClockModel.
> It removes unrelated logic from SystemTrayItem and makes embeding these
> views easier.
> 
> TEST=ash_unittests
> BUG=none
> 
> Change-Id: I70b3a873c0ac259a05597d3f93b77fd7519dd462
> Reviewed-on: https://chromium-review.googlesource.com/1025615
> Commit-Queue: Tetsui Ohkubo <tetsui@chromium.org>
> Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#553433}

No-Presubmit: true
No-Tree-Checks: true
No-Try: true
BUG=none

Change-Id: Ife07647a589f9caa276788bae5dccff68bcf41a0
Reviewed-on: https://chromium-review.googlesource.com/1027272
Cr-Commit-Position: refs/heads/master@{#553488}