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- Changed notification helper to observe the
clipboard, and close the bubble if the clipboard
got changed.
- Refactored Bubble & Button classes to
base and derived classed, so it'd be easier
to support warning mode later.
- Moved some of the needed bubble constants
to a separate file.

Bug: 1167228
Change-Id: I103ef1c95e1036ba28d3c449ed801688d12d2868
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2632673Reviewed-by: Sergey Poromov <poromov@chromium.org>
Commit-Queue: Aya Elsayed <ayaelattar@chromium.org>
Cr-Commit-Position: refs/heads/master@{#844518}