[Fetch API] Fix redirect leak on "no-cors" requests

The spec issue is now fixed, and this CL follows the spec change[1].

1: https://github.com/whatwg/fetch/commit/14858d3e9402285a7ff3b5e47a22896ff3adc95d

Bug: 791324
Change-Id: Ic3e3955f43578b38fc44a5a6b2a1b43d56a2becb
Reviewed-on: https://chromium-review.googlesource.com/1023613
Reviewed-by: Tsuyoshi Horo <horo@chromium.org>
Commit-Queue: Yutaka Hirano <yhirano@chromium.org>
Cr-Commit-Position: refs/heads/master@{#552964}
bool HasNonEmptyLocationHeader(const FetchHeaderList* headers) {
  String value;
  if (!headers->Get(HTTPNames::Location, value))
    return false;
  return !value.IsEmpty();
}

bool HasNonEmptyLocationHeader(const FetchHeaderList* headers) {
  String value;
  if (!headers->Get(HTTPNames::Location, value))
    return false;
  return !value.IsEmpty();
}
