This is to make second build no-op in mac_asan builder. e.g. https://ci.chromium.org/p/webrtc/builders/luci.webrtc.try/mac_asan/15219 We can use output_dir to override default_output_dir of executable. https://gn.googlesource.com/gn/+/master/docs/reference.md#tool-variables confirm no-op step for this CL does not complain. https://ci.chromium.org/p/webrtc/builders/luci.webrtc.try/mac_asan/15305 Bug: chromium:914264 Change-Id: Ia1196280064703dcb08e208e91c704cce25a925c Reviewed-on: https://webrtc-review.googlesource.com/c/114180 Reviewed-by: Oleh Prypin <oprypin@webrtc.org> Commit-Queue: Takuto Ikuta <tikuta@google.com> Cr-Commit-Position: refs/heads/master@{#26013}