Update gn documentation for --ide=vs.

The default is VS 2017 as of 7295a84e468138d53fc1f2259d737768f52e803c.

Bug: 683729
Change-Id: I795011162e0a9f6c39af799b50d32587b0baed76
Reviewed-on: https://chromium-review.googlesource.com/821211
Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Commit-Queue: Eric Roman <eroman@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#523274}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: c851ab862aaf3d893863cf5a6150d8bf0a22e52a
2 files changed
tree: 5fea131534da607ce315bc7fd3f8dab28d63d20b
  1. tools/