Update "import DEPS" syntax and package_repo_resource.

recipe_engine:
  https://crrev.com/a42dce4e0b0db8bd6b7688030e723197919306db [engine] Rewrite/simplify loading infrastructure. (iannucci@chromium.org)

R=jchinlee@chromium.org, martiniss@chromium.org, tandrii@chromium.org

Recipe-Manual-Change: skia
Recipe-Manual-Change: skiabuildbot
Recipe-Manual-Change: build
Recipe-Manual-Change: build_limited_scripts_slave
Recipe-Manual-Change: infra
Recipe-Manual-Change: release_scripts
Bug: 914992
Change-Id: Ie3a3be9124e1ca4abd5e79af2f8c946b3ce906ff
Reviewed-on: https://chromium-review.googlesource.com/c/1464761
Commit-Queue: Robbie Iannucci <iannucci@chromium.org>
Reviewed-by: Stephen Martinis <martiniss@chromium.org>
Reviewed-by: Andrii Shyshkalov <tandrii@chromium.org>