[NoStatePrefetch] Do not send responses to renderer in prefetch mode.

content/common/resource_request.h

 // Copyright 2016 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.
 
 #ifndef CONTENT_COMMON_RESOURCE_REQUEST_H_
 #define CONTENT_COMMON_RESOURCE_REQUEST_H_
 
 #include <stdint.h>
 #include <string>
 
@@ skipping 155 matching lines @@
   // decide.
   LoFiState lofi_state = LOFI_UNSPECIFIED;
 
   // PlzNavigate: the stream url associated with a navigation. Used to get
   // access to the body of the response that has already been fetched by the
   // browser.
   GURL resource_body_stream_url;
 
   // Wether or not the initiator of this request is a secure context.
   bool initiated_in_secure_context = false;
+
+  // The response should be downloaded and stored in the network cache, but the
+  // not sent back to the renderer.
+  bool download_to_network_cache_only = false;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_COMMON_RESOURCE_REQUEST_H_