Network Error Logging: Add request method to reports

Per https://github.com/WICG/network-error-logging/issues/73, we need to
add the request method to NEL reports.

Bug: 748549
Change-Id: I306ce389612a8ac794be732a47744b18db8cb4e2
Reviewed-on: https://chromium-review.googlesource.com/1118525
Reviewed-by: Misha Efimov <mef@chromium.org>
Commit-Queue: Douglas Creager <dcreager@chromium.org>
Cr-Commit-Position: refs/heads/master@{#575635}
5 files changed