Implement DialogPlate motion spec.

Known issues
- Settings icon fades in/out. Will address in follow up.
- ActionView is just a wrapper now for a LogoView. Will do a follow up
  CL to further clean this up.

See bug for spec/demo.

Bug: b:111500701
Change-Id: Iee2902f0c34b33cce579a78fb91b4519a2dff8c7
Reviewed-on: https://chromium-review.googlesource.com/1137843
Commit-Queue: David Black <dmblack@google.com>
Reviewed-by: Xiaohui Chen <xiaohuic@chromium.org>
Cr-Commit-Position: refs/heads/master@{#575529}
6 files changed