Fire load event for link modulepreload with non-fetch errors

According to the spec comment, load events (instead of error events)
should be fired for modules with non-fetch errors such as parse errors.

Bug: 740886, 763597
Change-Id: I6074b36631e1299b90d52bc01e42c5ddeb957b31
Reviewed-on: https://chromium-review.googlesource.com/802251
Reviewed-by: Kouhei Ueno <kouhei@chromium.org>
Reviewed-by: Kunihiko Sakamoto <ksakamoto@chromium.org>
Commit-Queue: Hiroshige Hayashizaki <hiroshige@chromium.org>
Cr-Commit-Position: refs/heads/master@{#521726}
2 files changed