GitLab

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

Bug: 1018739
Change-Id: I03160ac3a6ca185583254526647a320aa7173c22
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2442833Reviewed-by: Ken Rockot <rockot@google.com>
Commit-Queue: Sylvain Defresne <sdefresne@chromium.org>
Cr-Commit-Position: refs/heads/master@{#813696}