GitLab

In guest mode print jobs did not appear in print management app. This
prevented users being able to cancel in-progress jobs.

Overriding GetBrowserContextToUse allows using an OTR profile so that
jobs appear in the app.

Added function BuildInstanceFor for creating PrintManagement service in
tests.

Bug: 1128690
Change-Id: I837afd57711505e7bf8ab93f9aa38ed16dc5d3d0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2412222
Commit-Queue: Gavin Williams <gavinwill@chromium.org>
Reviewed-by: Zentaro Kavanagh <zentaro@chromium.org>
Cr-Commit-Position: refs/heads/master@{#810812}