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..0027d72cea9bf5adb590bb18712f0673555bf96a 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 was verified from the network, either by
+  // direct load or by confirming the current cached copy is good.
+  bool network_verified;

[rvargas (doing something else), 2013/04/03 21:48:19]

We have two options:
1. Have a signal about network connectivity. (network_was_accessed,
was_network_fetched, network_used etc)
2. Have a signal about caching details.
(cache_verified or something like that)

I'm inclined to go with the first option, and in that case, the flag should be
set by the network transaction, not the cache... and that should be a more
reliable indicator (as in not everything goes through the cache).

[Randy Smith (Not in Mondays), 2013/04/04 19:42:49]

Done, but just confirming: Do we actually use the response_info_ from the
network when we're just verifying the cache entry?  Specifically, I don't see
response_ being overwritten with new_response_ in
HttpCache::Transacation::DoSuccessfulSendRequest() in the 304 case.

[rvargas (doing something else), 2013/04/04 20:13:12]

The field has to be updated on HttpCache::Transaction::DoUpdateCachedResponse()

+
   // True if the request was fetched over a SPDY channel.
   bool was_fetched_via_spdy;