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- Moves CSS for error messages from the cups printers page to the settings
shared style so that it can be reused by other error messages.
- Switches Printers Page from using a custom message to using a cr_toast.

Cq-Include-Trybots: master.tryserver.chromium.linux:closure_compilation
Change-Id: I979499a8762e2405497a2ef9f090246c775c5269
Reviewed-on: https://chromium-review.googlesource.com/996618Reviewed-by: Xiaoqian Dai <xdai@chromium.org>
Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Commit-Queue: Bailey Berro <baileyberro@chromium.org>
Cr-Commit-Position: refs/heads/master@{#557944}