GitLab

Remove deprecated_default_sources_assignment_filter and replace
it with explicit is_win, is_mac, etc. sections.

Bug: 1018739
Change-Id: I3b18cbad0acec25f6662e1e142225b46aac99614
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2445871
Commit-Queue: Sylvain Defresne <sdefresne@chromium.org>
Reviewed-by: Greg Thompson <grt@chromium.org>
Cr-Commit-Position: refs/heads/master@{#814316}