GitLab

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

Bug: 1018739
Change-Id: Ieec4e3400ce3fcfa77b184dbc509600a1e973bc7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2443093Reviewed-by: David Roger <droger@chromium.org>
Commit-Queue: David Roger <droger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#813129}