GitLab

AllDownloadEventNotifier will listen to SimpleDownloadManagerCoordinate.
And report all the download events to its observers.

BUG=942770

Change-Id: I29b1e573d9c1f0e8b05002499410f296b6873765
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1560446Reviewed-by: Shakti Sahu <shaktisahu@chromium.org>
Reviewed-by: David Trainor <dtrainor@chromium.org>
Commit-Queue: Min Qin <qinmin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#649719}