Change code to propagate errors/exceptions to the top, and throw only once.

Bug: v8:7684
Cq-Include-Trybots: luci.v8.try:v8_linux_noi18n_rel_ng
Change-Id: I9a2d15cc4931f5bf029d2a8d78ad86e61f8db452
Reviewed-on: https://chromium-review.googlesource.com/1066808
Commit-Queue: Sathya Gunasekaran <gsathya@chromium.org>
Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Cr-Commit-Position: refs/heads/master@{#53476}