GitLab

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

Bug: 1018739
Change-Id: I911b1aa65b22ad2b2db8059b39feee9479ab003d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2440608Reviewed-by: Luke Halliwell (slow) <halliwell@chromium.org>
Commit-Queue: Sylvain Defresne <sdefresne@chromium.org>
Cr-Commit-Position: refs/heads/master@{#813156}