Add metrics to track HTTP/0.9 usage for main frames and subresources

content/browser/loader/resource_loader.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.
 
 #include "content/browser/loader/resource_loader.h"
 
 #include <utility>
 
 #include "base/command_line.h"
 #include "base/location.h"
@@ skipping 691 matching lines @@
   }
 }
 
 void ResourceLoader::CallDidFinishLoading() {
   TRACE_EVENT_WITH_FLOW0("loading", "ResourceLoader::CallDidFinishLoading",
                          this, TRACE_EVENT_FLAG_FLOW_IN);
   delegate_->DidFinishLoading(this);
 }
 
 void ResourceLoader::RecordHistograms() {
   if (request_->response_info().network_accessed) {

[Bence, 2016/06/30 21:20:11]

Why is Net.HttpResponseInfo.ConnectionInfo only recorded if
response_info.network_accessed, but
Net.HttpResponseInfo.ConnectionInfo.MainFrame and
Net.HttpResponseInfo.ConnectionInfo.SubResource are recorded regardless of
response_info.network_accessed?

[mmenke, 2016/06/30 22:18:07]

I've gone back and forth on this numerous times:  Do we want all requests,
HTTP/HTTPS requests, or requests that went over the network.  I really want to
get at how much disabling HTTP/0.9 breaks, but it's not really clear what's the
most accurate count of that.

I'll go ahead and remove the old histogram, per below comment, and put the new
ones in this branch.

     UMA_HISTOGRAM_ENUMERATION("Net.HttpResponseInfo.ConnectionInfo",

[Bence, 2016/06/30 21:20:11]

Since you are changing enum ConnectionInfo, I propose that you obsolete
histogram Net.HttpResponseInfo.ConnectionInfo and either create a new histogram
Net.HttpResponseInfo.ConnectionInfo2, or simply delete lines 712--716.

[mmenke, 2016/06/30 22:18:06]

Removed and obsoleted.

                               request_->response_info().connection_info,
                               net::HttpResponseInfo::NUM_OF_CONNECTION_INFOS);
   }
 
   ResourceRequestInfoImpl* info = GetRequestInfo();
 
+  if (info->GetResourceType() == RESOURCE_TYPE_MAIN_FRAME) {
+    UMA_HISTOGRAM_ENUMERATION("Net.HttpResponseInfo.ConnectionInfo.SubResource",

[Bence, 2016/06/30 21:20:11]

I think you got the two branches backwards.

[mmenke, 2016/06/30 22:18:07]

Thanks for catching that!  Done.

+                              request_->response_info().connection_info,
+                              net::HttpResponseInfo::NUM_OF_CONNECTION_INFOS);
+  } else {
+    UMA_HISTOGRAM_ENUMERATION("Net.HttpResponseInfo.ConnectionInfo.MainFrame",
+                              request_->response_info().connection_info,
+                              net::HttpResponseInfo::NUM_OF_CONNECTION_INFOS);
+  }
+
   if (info->GetResourceType() == RESOURCE_TYPE_PREFETCH) {
     PrefetchStatus status = STATUS_UNDEFINED;
     TimeDelta total_time = base::TimeTicks::Now() - request_->creation_time();
 
     switch (request_->status().status()) {
       case net::URLRequestStatus::SUCCESS:
         if (request_->was_cached()) {
           status = STATUS_SUCCESS_FROM_CACHE;
           UMA_HISTOGRAM_TIMES("Net.Prefetch.TimeSpentPrefetchingFromCache",
                               total_time);
@@ skipping 14 matching lines @@
     }
 
     UMA_HISTOGRAM_ENUMERATION("Net.Prefetch.Pattern", status, STATUS_MAX);
   } else if (request_->response_info().unused_since_prefetch) {
     TimeDelta total_time = base::TimeTicks::Now() - request_->creation_time();
     UMA_HISTOGRAM_TIMES("Net.Prefetch.TimeSpentOnPrefetchHit", total_time);
   }
 }
 
 }  // namespace content