Improve ChromiumHttpConnection logging.

Previously, in the event of network error, only HTTP status code was
being factored into logging. We want to print as much information as
is available to assist in debugging in the event of network error.

See bug for before/after.

Bug: b:132901765
Change-Id: I51d23c00e3533156f02d9ecc3b9e5f726ef74537
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1614446
Reviewed-by: Xiaohui Chen <xiaohuic@chromium.org>
Reviewed-by: Chris Mumford <cmumford@google.com>
Commit-Queue: David Black <dmblack@google.com>
Cr-Commit-Position: refs/heads/master@{#664310}