Fuchsia: Implement handle passing in FIDL/JS

Bug: 883496
Change-Id: Ia5a0e88ca4a1d41c6be4f81a4dc4cc46b74930a7
Reviewed-on: https://chromium-review.googlesource.com/c/1311082
Commit-Queue: Scott Graham <scottmg@chromium.org>
Reviewed-by: Wez <wez@chromium.org>
Cr-Commit-Position: refs/heads/master@{#605405}
5 files changed