commit 305da9c0a4f8271ca04730321cd3fca11a614ed2
author Sean Abraham <seanabraham@chromium.org> Tue Jan 21 18:56:17 2020
committer Commit Bot <commit-bot@chromium.org> Tue Jan 21 21:03:44 2020
tree 19af0cd421362df156a09b4a080f1332f0ab01be
parent 87b601aa569ba82e4399990eca42312a1a0ac9fc

build_checker: return pointless when no affected files

This makes behavior more obvious, and it supports Chris's use case for
toolchain. The build_target recipe is now skipping running the pointless
build checker when there are no Gerrit changes, so this maintains
present behavior for postsubmit.

BUG=chromium:1041976
TEST=unit tests

Change-Id: Id427cd8ce30bf94980b444ffe4f2de76eaf23c45
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/infra/go/+/2012993
Reviewed-by: Sean Abraham <seanabraham@chromium.org>
Tested-by: Sean Abraham <seanabraham@chromium.org>
Commit-Queue: Chris McDonald <cjmcdonald@chromium.org>