GitLab

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

Bug: 1018739
Change-Id: I276656a5128181e9b5c93fc8c93df9fd5d255999
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2445416Reviewed-by: Derek Schuff <dschuff@chromium.org>
Commit-Queue: Sylvain Defresne <sdefresne@chromium.org>
Cr-Commit-Position: refs/heads/master@{#814248}