GitLab

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

TBR=skyostil@chromium.org

Bug: 1018739
Change-Id: I163c10cfb9ff34ad117fb0b74b6c598a09cfe61c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2442795
Commit-Queue: Sylvain Defresne <sdefresne@chromium.org>
Auto-Submit: Sylvain Defresne <sdefresne@chromium.org>
Reviewed-by: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#814664}