[CORS-RFC1918] Use response URL to compute address space.

This aligns the code computing `document.addressSpace` with what I
believe should be laid out in the spec (PR to come).

  https://wicg.github.io/cors-rfc1918/#address-space

At a high level, we want the address space to reflect where the response
data actually came from.

Bug: chromium:1142505
Change-Id: Ib7ba5cdca407c3c86af5b58c7c9da982dc355c72
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2460824
Commit-Queue: Titouan Rigoudy <titouan@chromium.org>
Commit-Queue: Matt Menke <mmenke@chromium.org>
Reviewed-by: Matt Menke <mmenke@chromium.org>
Reviewed-by: Mike West <mkwst@chromium.org>
Auto-Submit: Titouan Rigoudy <titouan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#822805}

services/network/public/cpp/ip_address_space_util.cc

@@ -44,10 +44,25 @@ bool IsLessPublicAddressSpace(IPAddressSpace lhs, IPAddressSpace rhs) {
   return CollapseUnknown(lhs) < CollapseUnknown(rhs);
 }
 
+// Helper for CalculateClientAddressSpace() with the same arguments.
+//
+// If the response was fetched via service workers, returns the last URL in the
+// list. Otherwise returns |request_url|.
+//
+// See: https://fetch.spec.whatwg.org/#concept-response-url-list
+const GURL& ResponseUrl(const GURL& request_url,
+                        const mojom::URLResponseHead* response_head) {
+  if (response_head && !response_head->url_list_via_service_worker.empty()) {
+    return response_head->url_list_via_service_worker.back();
+  }
+
+  return request_url;
+}
+
 IPAddressSpace CalculateClientAddressSpace(
     const GURL& url,
     const mojom::URLResponseHead* response_head) {
-  if (url.SchemeIsFile()) {
+  if (ResponseUrl(url, response_head).SchemeIsFile()) {
     // See: https://wicg.github.io/cors-rfc1918/#file-url.
     return IPAddressSpace::kLocal;
   }

services/network/public/cpp/ip_address_space_util_unittest.cc

@@ -113,6 +113,40 @@ TEST(IPAddressSpaceTest, CalculateClientAddressSpaceFileURL) {
             CalculateClientAddressSpace(GURL("file:///foo"), nullptr));
 }
 
+TEST(IPAddressSpaceTest,
+     CalculateIPAddressSpaceFetchedViaServiceWorkerFromFile) {
+  URLResponseHead response_head;
+  response_head.url_list_via_service_worker.emplace_back("http://bar.test");
+  response_head.url_list_via_service_worker.emplace_back("file:///foo");
+  response_head.parsed_headers = ParsedHeaders::New();
+
+  EXPECT_EQ(
+      IPAddressSpace::kLocal,
+      CalculateClientAddressSpace(GURL("http://foo.test"), &response_head));
+}
+
+TEST(IPAddressSpaceTest,
+     CalculateIPAddressSpaceFetchedViaServiceWorkerFromHttp) {
+  URLResponseHead response_head;
+  response_head.url_list_via_service_worker.emplace_back("file:///foo");
+  response_head.url_list_via_service_worker.emplace_back("http://bar.test");
+  response_head.parsed_headers = ParsedHeaders::New();
+
+  EXPECT_EQ(
+      IPAddressSpace::kUnknown,
+      CalculateClientAddressSpace(GURL("http://foo.test"), &response_head));
+}
+
+TEST(IPAddressSpaceTest,
+     CalculateIPAddressSpaceFetchedViaServiceWorkerFromHttpInsteadOfFile) {
+  URLResponseHead response_head;
+  response_head.url_list_via_service_worker.emplace_back("http://bar.test");
+  response_head.parsed_headers = ParsedHeaders::New();
+
+  EXPECT_EQ(IPAddressSpace::kUnknown,
+            CalculateClientAddressSpace(GURL("file:///foo"), &response_head));
+}
+
 TEST(IPAddressSpaceTest, CalculateClientAddressSpaceNullResponseHead) {
   EXPECT_EQ(IPAddressSpace::kUnknown,
             CalculateClientAddressSpace(GURL("http://foo.test"), nullptr));