Without this, on some build configurations the symbols of the specialized members don't get exported as explained at: https://bugs.chromium.org/p/chromium/issues/detail?id=1026078#c10 Bug: chromium:1026078 Change-Id: I0c3058a82d60e6de5e401dbec5bb8501b7bbd8b5 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/160046 Reviewed-by: Karl Wiberg <kwiberg@webrtc.org> Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org> Cr-Commit-Position: refs/heads/master@{#29846}