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

content/common/resource_request.h

Index: content/common/resource_request.h
diff --git a/content/common/resource_request.h b/content/common/resource_request.h
index 83263cc5c1ccd40cdbae11011e65143a32e1fd3d..f92e2d35bd882c0360bc859a7b2528d4dbf9ac62 100644
--- a/content/common/resource_request.h
+++ b/content/common/resource_request.h
@@ -173,6 +173,10 @@ struct CONTENT_EXPORT ResourceRequest {
 
   // 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 not
+  // sent back to the renderer.
+  bool download_to_network_cache_only = false;
 };
 
 }  // namespace content