Revert "Implement tracking of BUILD.gn files ..."

This change reverts reverts commit 44fd682d (#483337);
it looks like it doesn't correctly handle at least
changes to the default configs.

TBR=brettw@chromium.org, alex-ac@yandex-team.ru, thakis@chromium.org
BUG=755622

Change-Id: Ic8ad61736ad208bcce6004e8047febf405c001e1
Reviewed-on: https://chromium-review.googlesource.com/617774
Commit-Queue: Dirk Pranke <dpranke@chromium.org>
Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#495174}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: c9126ec981a4f32d6219cee1eee3a976dba5cead
48 files changed
tree: 6b93bc9c99e95d8246a60f9c79e350661dc71432
  1. tools/