Enable MetaColorScheme and CSSColorScheme flags.

Intent to ship thread:

https://groups.google.com/a/chromium.org/forum/#!topic/blink-dev/-_0REgUR-yY

Bug: 939811, 925935
Change-Id: I00e1b7ffc162b2b226db1a722391a61a5386cb51
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2027328
Reviewed-by: Anders Hartvoll Ruud <andruud@chromium.org>
Reviewed-by: Chris Harrelson <chrishtr@chromium.org>
Commit-Queue: Chris Harrelson <chrishtr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#736650}
20 files changed