Fuchsia: Fix handling of nullable vectors in FIDL/JS

Bug: 883496
Change-Id: I656ef4172089f65b6febf0ba3075a510bb4e9e11
Reviewed-on: https://chromium-review.googlesource.com/c/1318835
Commit-Queue: Scott Graham <scottmg@chromium.org>
Reviewed-by: Wez <wez@chromium.org>
Cr-Commit-Position: refs/heads/master@{#606354}
3 files changed