Disable CORS check in FileURLLoader

It was introduced for out-of-blink CORS, but the check doesn't work with
extensions. Until it's fixes let's rely on the renderer side check and
disable the check.

Bug: 895999
Change-Id: I59aaafcb9185e1937372cf8967ef45d3728dff64
Reviewed-on: https://chromium-review.googlesource.com/c/1335078
Commit-Queue: Yutaka Hirano <yhirano@chromium.org>
Reviewed-by: John Abd-El-Malek <jam@chromium.org>
Reviewed-by: Takashi Toyoshima <toyoshim@chromium.org>
Reviewed-by: Marijn Kruisselbrink <mek@chromium.org>
Cr-Commit-Position: refs/heads/master@{#609213}

content/browser/file_url_loader_factory.cc

@@ -10,6 +10,7 @@
 #include <vector>
 
 #include "base/bind.h"
+#include "base/feature_list.h"
 #include "base/files/file.h"
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
@@ -40,6 +41,7 @@
 #include "net/http/http_util.h"
 #include "net/url_request/redirect_info.h"
 #include "services/network/public/cpp/cors/cors_error_status.h"
+#include "services/network/public/cpp/features.h"
 #include "services/network/public/cpp/resource_request.h"
 #include "services/network/public/mojom/cors.mojom-shared.h"
 #include "services/network/public/mojom/url_loader.mojom.h"
@@ -102,6 +104,12 @@ bool ShouldFailRequestDueToCors(const network::ResourceRequest& request) {
     return false;
   }
 
+  // Currently the following logic does not work with extensions. Until it's
+  // fixed let's rely on the renderer-side check. See https://crbug.com/895999.
+  if (!base::FeatureList::IsEnabled(network::features::kOutOfBlinkCors)) {
+    return false;
+  }
+
   const auto mode = request.fetch_request_mode;
   if (mode == network::mojom::FetchRequestMode::kNavigate ||
       mode == network::mojom::FetchRequestMode::kNoCors) {