This means that by default, targets are visible to everything under the WebRTC root, but not visible to anything else. API targets are manually tagged with visibility "*", so that targets outside the WebRTC tree can see them. BUG=webrtc:8254 Change-Id: Icdbee6e0d22d93240ff2fb530c8f9dc48e351509 Reviewed-on: https://webrtc-review.googlesource.com/24140 Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org> Commit-Queue: Karl Wiberg <kwiberg@webrtc.org> Cr-Commit-Position: refs/heads/master@{#21548}