Make PlatformNotificationContext display all notifications.

This hands off the display call to PlatformNotificationContext which
gets rid of some code duplication as we always want to show a
notification after writing it into the NotificationDatabase.

Bug: 891339
Change-Id: If0787fcd9668cb0e419edcc16a56c91649983dcc
Reviewed-by: Avi Drissman <>
Reviewed-by: Peter Beverloo <>
Commit-Queue: Richard Knoll <>
Cr-Commit-Position: refs/heads/master@{#643370}
7 files changed