GitLab

Migrates pdf_compositor from ServiceContext to ServiceBinding and makes
its tests regular unit tests instead of using the deprecated ServiceTest
framework.

TBR=thestig@chromium.org

Bug: 891780,906239
Change-Id: Ia2485320e71352b3263108544fbea06c6b8ca6ef
Reviewed-on: https://chromium-review.googlesource.com/c/1343506Reviewed-by: Ken Rockot <rockot@google.com>
Reviewed-by: Jochen Eisinger <jochen@chromium.org>
Reviewed-by: Robert Sesek <rsesek@chromium.org>
Reviewed-by: Sami Kyöstilä <skyostil@chromium.org>
Reviewed-by: Wei Li <weili@chromium.org>
Commit-Queue: Ken Rockot <rockot@google.com>
Cr-Commit-Position: refs/heads/master@{#610340}