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In this CL create a simple dialog with a close button. The dialog also
displays Share/Scan tabs but no functionality is implemented for those.

screenshot:
https://screenshot.googleplex.com/JHExGzx6ds6.png

Bug: 993920
Change-Id: I056c8397d640092ac7c3aa56e3d0a983a9551cf0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1869884
Commit-Queue: Gayane Petrosyan <gayane@chromium.org>
Reviewed-by: Theresa  <twellington@chromium.org>
Reviewed-by: David Trainor <dtrainor@chromium.org>
Cr-Commit-Position: refs/heads/master@{#709243}