GitLab

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

Bug: 1018739
Change-Id: If84d88a29e4dc9602494d16446b6b85eefc35149
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2445476Reviewed-by: Matthew Denton <mpdenton@chromium.org>
Commit-Queue: Sylvain Defresne <sdefresne@chromium.org>
Cr-Commit-Position: refs/heads/master@{#813681}