Persist HTTP RTT and Transport RTT estimates in UKM on navigation start.

chrome/browser/page_load_metrics/observers/ukm_page_load_metrics_observer.cc

 // Copyright 2017 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 "chrome/browser/page_load_metrics/observers/ukm_page_load_metrics_observer.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/net/nqe/ui_network_quality_estimator_service.h"
 #include "chrome/browser/net/nqe/ui_network_quality_estimator_service_factory.h"
 #include "chrome/browser/page_load_metrics/page_load_metrics_util.h"
 #include "chrome/browser/profiles/profile.h"
@@ skipping 10 matching lines @@
 const char kUkmLoadEventName[] = "DocumentTiming.NavigationToLoadEventFired";
 const char kUkmFirstContentfulPaintName[] =
     "PaintTiming.NavigationToFirstContentfulPaint";
 const char kUkmFirstMeaningfulPaintName[] =
     "Experimental.PaintTiming.NavigationToFirstMeaningfulPaint";
 const char kUkmForegroundDurationName[] = "PageTiming.ForegroundDuration";
 const char kUkmFailedProvisionaLoadName[] =
     "PageTiming.NavigationToFailedProvisionalLoad";
 const char kUkmEffectiveConnectionType[] =
     "Net.EffectiveConnectionType.OnNavigationStart";
+const char kUkmHttpRttEstimate[] = "Net.HttpRttEstimate.OnNavigationStart";
+const char kUkmTransportRttEstimate[] =
+    "Net.TransportRttEstimate.OnNavigationStart";
 const char kUkmNetErrorCode[] = "Net.ErrorCode.OnFailedProvisionalLoad";
 const char kUkmPageTransition[] = "Navigation.PageTransition";
 
 }  // namespace internal
 
 namespace {
 
 UINetworkQualityEstimatorService* GetNQEService(
     content::WebContents* web_contents) {
   Profile* profile =
@@ skipping 33 matching lines @@
   // When OnStart is invoked, we don't yet know whether we're observing a web
   // page load, vs another kind of load (e.g. a download or a PDF). Thus,
   // metrics and source information should not be recorded here. Instead, we
   // store data we might want to persist in member variables below, and later
   // record UKM metrics for that data once we've confirmed that we're observing
   // a web page load.
 
   if (network_quality_provider_) {
     effective_connection_type_ =
         network_quality_provider_->GetEffectiveConnectionType();
+    http_rtt_estimate_ = network_quality_provider_->GetHttpRTT();
+    transport_rtt_estimate_ = network_quality_provider_->GetTransportRTT();
   }
   page_transition_ = navigation_handle->GetPageTransition();
   return CONTINUE_OBSERVING;
 }
 
 UkmPageLoadMetricsObserver::ObservePolicy UkmPageLoadMetricsObserver::OnCommit(
     content::NavigationHandle* navigation_handle) {
   // The PageTransition for the navigation may be updated on commit.
   page_transition_ = navigation_handle->GetPageTransition();
   return CONTINUE_OBSERVING;
@@ skipping 86 matching lines @@
       page_load_metrics::GetInitialForegroundDuration(info,
                                                       app_background_time);
   if (foreground_duration) {
     builder->AddMetric(internal::kUkmForegroundDurationName,
                        foreground_duration.value().InMilliseconds());
   }
   if (effective_connection_type_ != net::EFFECTIVE_CONNECTION_TYPE_UNKNOWN) {
     builder->AddMetric(internal::kUkmEffectiveConnectionType,
                        static_cast<int64_t>(effective_connection_type_));
   }
+  if (http_rtt_estimate_) {
+    builder->AddMetric(
+        internal::kUkmHttpRttEstimate,
+        static_cast<int64_t>(http_rtt_estimate_.value().InMilliseconds()));
+  }
+  if (transport_rtt_estimate_) {
+    builder->AddMetric(
+        internal::kUkmTransportRttEstimate,
+        static_cast<int64_t>(transport_rtt_estimate_.value().InMilliseconds()));
+  }
   // page_transition_ fits in a uint32_t, so we can safely cast to int64_t.
   builder->AddMetric(internal::kUkmPageTransition,
                      static_cast<int64_t>(page_transition_));
 }