Convert ebuild to pull chrome sources from git.

Re-landing this:

https://chromium-review.googlesource.com/212790

It should work now, after this change to gclient:

https://codereview.chromium.org/490233003

... and after rolling that change into the manifest:

https://chromium-review.googlesource.com/#/c/213524/
https://chrome-internal-review.googlesource.com/#/c/173395/

BUG=chromium:376027
TEST=scripts/cros_mark_chrome_as_stable_unittest.py

Change-Id: I20c2a6d3a221fae0a3849628b688cded996834b4
Reviewed-on: https://chromium-review.googlesource.com/213460
Reviewed-by: David James <davidjames@chromium.org>
Tested-by: Stefan Zager <szager@chromium.org>
(cherry picked from commit d49d9ff866f4c333f48128f852aea8de37cc3715)
Reviewed-on: https://chromium-review.googlesource.com/214158
Reviewed-by: Dharani Govindan <dharani@chromium.org>
Tested-by: Dharani Govindan <dharani@chromium.org>
11 files changed