[COEP] Change error code for COEP blocked navigations..

..from net::ERR_FAILED to net::ERR_BLOCKED_BY_RESPONSE. This is more
precise, as the navigation was blocked.

Bug: chromium:1051466
Change-Id: Ic3b7166a581710610f00fee197afbd0dcc2e9f14
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2066748
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Reviewed-by: Pâris Meuleman <pmeuleman@chromium.org>
Reviewed-by: Camille Lamy <clamy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#743917}

content/browser/frame_host/navigation_request.cc

@@ -1753,7 +1753,7 @@ void NavigationRequest::OnResponseStarted(
       if (cross_origin_embedder_policy ==
           network::mojom::CrossOriginEmbedderPolicy::kNone) {
         OnRequestFailedInternal(
-            network::URLLoaderCompletionStatus(net::ERR_FAILED),
+            network::URLLoaderCompletionStatus(net::ERR_BLOCKED_BY_RESPONSE),
             false /* skip_throttles */, base::nullopt /* error_page_content */,
             false /* collapse_frame */);
         // DO NOT ADD CODE after this. The previous call to
@@ -1772,7 +1772,7 @@ void NavigationRequest::OnResponseStarted(
         (frame_tree_node_->pending_frame_policy().sandbox_flags !=
          blink::mojom::WebSandboxFlags::kNone)) {
       OnRequestFailedInternal(
-          network::URLLoaderCompletionStatus(net::ERR_FAILED),
+          network::URLLoaderCompletionStatus(net::ERR_BLOCKED_BY_RESPONSE),
           false /* skip_throttles */, base::nullopt /* error_page_content */,
           false /* collapse_frame */);
       // DO NOT ADD CODE after this. The previous call to