Expose SPDY pushes in DevTools

net/base/load_timing_info.h

 // Copyright (c) 2012 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 NET_BASE_LOAD_TIMING_INFO_H_
 #define NET_BASE_LOAD_TIMING_INFO_H_
 
 #include <stdint.h>
 
 #include "base/time/time.h"
@@ skipping 20 matching lines @@
 // dns_start
 // dns_end
 // connect_start
 // ssl_start
 // ssl_end
 // connect_end
 // send_start
 // send_end
 // receive_headers_end
 //
-// Times represent when a request starts/stops blocking on an event, not the
-// time the events actually occurred.  In particular, in the case of preconnects
+// Times represent when a request starts/stops blocking on an event(*), not the
+// time the events actually occurred. In particular, in the case of preconnects
 // and socket reuse, no time may be spent blocking on establishing a connection.
 // In the case of SPDY, PAC scripts are only run once for each shared session,
 // so no time may be spent blocking on them.
 //
+// (*) Note 1: push_start and push_end are the exception to this, as they
+// represent the operation which is asynchronous to normal request flow and
+// hence are provided as absolute values and not converted to "blocking" time.
+//
+// (*) Note 2: Internally to the network stack, times are those of actual event
+// occurrence. URLRequest converts them to time which the network stack was
+// blocked on each state, as per resource timing specs.
+//
 // DNS and SSL times are both times for the host, not the proxy, so DNS times
 // when using proxies are null, and only requests to HTTPS hosts (Not proxies)
 // have SSL times.  One exception to this is when a proxy server itself returns
 // a redirect response.  In this case, the connect times treat the proxy as the
 // host.  The send and receive times will all be null, however.
 // See HttpNetworkTransaction::OnHttpsProxyTunnelResponse.
 // TODO(mmenke):  Is this worth fixing?
 //
-// Note that internal to the network stack, times are when events actually
-// occurred.  URLRequest converts them to time which the network stack was
-// blocked on each state.
 struct NET_EXPORT LoadTimingInfo {
   // Contains the LoadTimingInfo events related to establishing a connection.
   // These are all set by ConnectJobs.
   struct NET_EXPORT_PRIVATE ConnectTiming {
     ConnectTiming();
     ~ConnectTiming();
 
     // The time spent looking up the host's DNS address.  Null for requests that
     // used proxies to look up the DNS address.  Also null for SOCKS4 proxies,
     // since the DNS address is only looked up after the connection is
@@ skipping 61 matching lines @@
   base::TimeTicks proxy_resolve_end;
 
   ConnectTiming connect_timing;
 
   // The time that sending HTTP request started / ended.
   base::TimeTicks send_start;
   base::TimeTicks send_end;
 
   // The time at which the end of the HTTP headers were received.
   base::TimeTicks receive_headers_end;
+
+  // In case the resource was proactively pushed by the server, these are
+  // the times that push started and ended. Note that push_end will be null
+  // if the request is still being transmitted, i.e. the underlying h2 stream
+  // is not closed by the server.
+  base::TimeTicks push_start;
+  base::TimeTicks push_end;
 };
 
 }  // namespace net
 
 #endif  // NET_BASE_LOAD_TIMING_INFO_H_