GitLab

When full browser is not launched, we should create InProgressDownloadManager
to handle all the operations.

BUG=842245

Change-Id: I2687000288c9459c8df8099ff4721a2b6755d96e
Reviewed-on: https://chromium-review.googlesource.com/c/1297237
Commit-Queue: Min Qin <qinmin@chromium.org>
Reviewed-by: Xing Liu <xingliu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#602097}