IsBannedCrossSiteAuth() to use IsSchemelesslyFirstParty()

IsFirstParty() changed recently to depend on the SchemefulSameSite
feature. When SchemefulSameSite is enabled IsFirstParty() won't behave
as IsBannedCrossSiteAuth() is expecting.

This CL changes IsFirstParty() to only check URLs schemelessly which
aligns with current behavior and IsBannedCrossSiteAuth()'s expectations.

Bug: 1030938
Change-Id: I3cfe190c530333fde0d9292899a2f71d8d813364
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2146300Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Commit-Queue: Steven Bingler <bingler@chromium.org>
Cr-Commit-Position: refs/heads/master@{#759291}

content/renderer/loader/web_url_loader_impl.cc

@@ -305,7 +305,7 @@ bool IsBannedCrossSiteAuth(network::ResourceRequest* resource_request,
         extra_data->allow_cross_origin_auth_prompt();
   }
 
-  if (first_party.IsFirstParty(request_url)) {
+  if (first_party.IsSchemelesslyFirstParty(request_url)) {
     // If the first party is secure but the subresource is not, this is
     // mixed-content. Do not allow the image.
     if (!allow_cross_origin_auth_prompt &&