Expose SPDY pushes in DevTools

content/child/resource_dispatcher.cc

 // 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.
 
 // See http://dev.chromium.org/developers/design-documents/multi-process-resource-loading
 
 #include "content/child/resource_dispatcher.h"
 
 #include <utility>
 
@@ skipping 614 matching lines @@
   RemoteToLocalTimeTicks(converter, &load_timing->proxy_resolve_end);
   RemoteToLocalTimeTicks(converter, &load_timing->connect_timing.dns_start);
   RemoteToLocalTimeTicks(converter, &load_timing->connect_timing.dns_end);
   RemoteToLocalTimeTicks(converter, &load_timing->connect_timing.connect_start);
   RemoteToLocalTimeTicks(converter, &load_timing->connect_timing.connect_end);
   RemoteToLocalTimeTicks(converter, &load_timing->connect_timing.ssl_start);
   RemoteToLocalTimeTicks(converter, &load_timing->connect_timing.ssl_end);
   RemoteToLocalTimeTicks(converter, &load_timing->send_start);
   RemoteToLocalTimeTicks(converter, &load_timing->send_end);
   RemoteToLocalTimeTicks(converter, &load_timing->receive_headers_end);
+  RemoteToLocalTimeTicks(converter, &load_timing->push_start);
+  RemoteToLocalTimeTicks(converter, &load_timing->push_end);

[mmenke, 2016/03/25 14:50:28]

This is somewhat weird...Since renderer process times != browser process times,
we need some conversion.  What this code does is take two known times from the
renderer, two known times from the browser, and a bunch of times between them,
and linearly interpolate those intermediary times from browser to renderer
times.  This mostly works... at least we don't do anything crazy...  *However* 
push_start and push_end can be outside that range, and if a request is fast, we
could have, say, a renderer delta of 100 milliseconds, and a browser delta of 10
milliseconds.  Then interpolation becomes a real source of error here.

Have you thought about this?

   RemoteToLocalTimeTicks(converter, &renderer_info->service_worker_start_time);
   RemoteToLocalTimeTicks(converter, &renderer_info->service_worker_ready_time);
 
   // Collect UMA on the inter-process skew.
   bool is_skew_additive = false;
   if (converter.IsSkewAdditiveForMetrics()) {
     is_skew_additive = true;
     base::TimeDelta skew = converter.GetSkewForMetrics();
     if (skew >= base::TimeDelta()) {
       UMA_HISTOGRAM_TIMES(
@@ skipping 163 matching lines @@
     *frame_origin = extra_data->frame_origin();
   return request;
 }
 
 void ResourceDispatcher::SetResourceSchedulingFilter(
     scoped_refptr<ResourceSchedulingFilter> resource_scheduling_filter) {
   resource_scheduling_filter_ = resource_scheduling_filter;
 }
 
 }  // namespace content