Fix web_accesible_resources enforcement for Site Isolation.

content/browser/loader/navigation_resource_throttle.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/loader/navigation_resource_throttle.h"
 
 #include <memory>
 
 #include "base/bind.h"
 #include "base/callback.h"
@@ skipping 241 matching lines @@
   return "NavigationResourceThrottle";
 }
 
 void NavigationResourceThrottle::OnUIChecksPerformed(
     NavigationThrottle::ThrottleCheckResult result) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   if (result == NavigationThrottle::CANCEL_AND_IGNORE) {
     controller()->CancelAndIgnore();
   } else if (result == NavigationThrottle::CANCEL) {
     controller()->Cancel();
+  } else if (result == NavigationThrottle::BLOCK_REQUEST) {
+    controller()->CancelWithError(net::ERR_BLOCKED_BY_CLIENT);
   } else {
     controller()->Resume();
   }
 }
 
 }  // namespace content