Fix error handling in the request sender and url fetcher downloader.

That means handling the network errors by primarily looking at net_error.

Bug: 1028369
Change-Id: I8181bced25f8b56144ea336a03883d0dceea5108
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1935428
Reviewed-by: Joshua Pawlicki <waffles@chromium.org>
Commit-Queue: Sorin Jianu <sorin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#719199}
void UrlFetcherDownloader::OnResponseStarted(int response_code,
                                             int64_t content_length) {
  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);

  VLOG(1) << "url fetcher response started for: " << url().spec();

  response_code_ = response_code;
  total_bytes_ = content_length;
}

void UrlFetcherDownloader::OnResponseStarted(int response_code,
                                             int64_t content_length) {
  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);

  VLOG(1) << "url fetcher response started for: " << url().spec();

  response_code_ = response_code;
  total_bytes_ = content_length;
}
