GitLab

We dispatch CORS preflight events only when there is an event listener
with "extraHeaders" specified. Hence some extension developers may
want to specify that option for onBeforeReuqest and onErrorOcurred.

Bug: 1002884
Change-Id: I7006f9b30c94858427b66aa2fd93d82e4f8f4c37
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1866374
Commit-Queue: Yutaka Hirano <yhirano@chromium.org>
Reviewed-by: Karan Bhatia <karandeepb@chromium.org>
Auto-Submit: Yutaka Hirano <yhirano@chromium.org>
Cr-Commit-Position: refs/heads/master@{#707642}