Create dummy DEPS entry for Chromium. Never actually check out Chromium. Required by autoroller to support updating chromium_revision var. Bug: skia:10572 Change-Id: I8c88a42286f010d2702f9ff646c7bb344153d2fe Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2353730 Commit-Queue: Yuly Novikov <ynovikov@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org>