Add NetworkIsolationKey for browser_test_utils

Set NetworkIsolationKey for LoadBasicRequest() in browser_test_utils.cc
Similar to site_for_cookies, the NetworkIsolationKey is set to the
origin of the url that is requested.

Bug: 989067
Change-Id: Idf25303d3fecb0079ab74184765d66999649ae64
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1764198Reviewed-by: Yao Xiao <yaoxia@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Christian Dullweber <dullweber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#690314}

content/public/test/browser_test_utils.cc

@@ -3145,6 +3145,9 @@ int LoadBasicRequest(network::mojom::NetworkContext* network_context,
       network::mojom::URLLoaderFactoryParams::New();
   url_loader_factory_params->process_id = process_id;
   url_loader_factory_params->is_corb_enabled = false;
+  url::Origin origin = url::Origin::Create(url);
+  url_loader_factory_params->network_isolation_key =
+      net::NetworkIsolationKey(origin, origin);
   network_context->CreateURLLoaderFactory(MakeRequest(&url_loader_factory),
                                           std::move(url_loader_factory_params));
   // |url_loader_factory| will receive error notification asynchronously if