Implement offline mode behind a flag

net/http/http_response_info.h

Index: net/http/http_response_info.h
diff --git a/net/http/http_response_info.h b/net/http/http_response_info.h
index c82dd07213e999cb08f11e89b2f048e93605f3b6..0af8dd5d141f35559fa81ff2114c3b649528b4d3 100644
--- a/net/http/http_response_info.h
+++ b/net/http/http_response_info.h
@@ -64,6 +64,10 @@ class NET_EXPORT HttpResponseInfo {
   // was unable to contact the server.
   bool server_data_unavailable;
 
+  // True if the request accessed the network in the process of retrieving
+  // data.
+  bool network_accessed;
+
   // True if the request was fetched over a SPDY channel.
   bool was_fetched_via_spdy;