GN: Schedule config loads for sub-configs.

Previously the Builder did not schedule file loads for configs of configs.

This meant that if a BUILD file contained only configs referenced by other
configs (rather than configs referenced by targets, or targets referenced by
other targets), it would never be loaded. The result will be a failed run with
an undefined object.

BUG=536844

Review URL: https://codereview.chromium.org/1373903002

Cr-Original-Commit-Position: refs/heads/master@{#351089}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 1b1e7e8c8f3105b6c9811ff28947961eb96153c3
2 files changed
tree: 33717d4300724ddc43fc6960bf383d851948ed78
  1. tools/