Expose RTT and downlink bandwidth using experimental Javascript API

third_party/WebKit/Source/platform/network/NetworkStateNotifier.cpp

Index: third_party/WebKit/Source/platform/network/NetworkStateNotifier.cpp
diff --git a/third_party/WebKit/Source/platform/network/NetworkStateNotifier.cpp b/third_party/WebKit/Source/platform/network/NetworkStateNotifier.cpp
index 800557c4944a1482b505a4102315481a86d2e06d..2f7553d732c5d75014b3edf101c4e1fbe7997a15 100644
--- a/third_party/WebKit/Source/platform/network/NetworkStateNotifier.cpp
+++ b/third_party/WebKit/Source/platform/network/NetworkStateNotifier.cpp
@@ -58,7 +58,10 @@ NetworkStateNotifier::ScopedNotifier::~ScopedNotifier() {
   const NetworkState& after =
       notifier_.has_override_ ? notifier_.override_ : notifier_.state_;
   if ((after.type != before_.type ||
-       after.max_bandwidth_mbps != before_.max_bandwidth_mbps) &&
+       after.max_bandwidth_mbps != before_.max_bandwidth_mbps ||
+       after.http_rtt != before_.http_rtt ||
+       after.transport_rtt != before_.transport_rtt ||
+       after.downlink_throughput_mbps != before_.downlink_throughput_mbps) &&
       before_.connection_initialized) {
     notifier_.NotifyObservers(notifier_.connection_observers_,
                               ObserverType::CONNECTION_TYPE, after);
@@ -91,6 +94,28 @@ void NetworkStateNotifier::SetWebConnection(WebConnectionType type,
   }
 }
 
+void NetworkStateNotifier::SetNetworkQuality(TimeDelta http_rtt,
+                                             TimeDelta transport_rtt,
+                                             int downlink_throughput_kbps) {
+  DCHECK(IsMainThread());
+  ScopedNotifier notifier(*this);
+  {
+    MutexLocker locker(mutex_);
+
+    state_.http_rtt =
+        http_rtt.InMilliseconds() < 0 ? Optional<TimeDelta>() : http_rtt;

[dcheng, 2017/05/17 12:27:46]

Nit: does nullopt instead of Optional<TimeDelta>() work here? Same question
below.

[tbansal1, 2017/05/18 00:10:30]

Done.

+
+    state_.transport_rtt = transport_rtt.InMilliseconds() < 0
+                               ? Optional<TimeDelta>()
+                               : transport_rtt;
+
+    state_.downlink_throughput_mbps =
+        downlink_throughput_kbps < 0
+            ? Optional<double>()
+            : static_cast<double>(downlink_throughput_kbps) / 1000;
+  }
+}
+
 void NetworkStateNotifier::AddConnectionObserver(
     NetworkStateObserver* observer,
     PassRefPtr<WebTaskRunner> task_runner) {
@@ -180,8 +205,9 @@ void NetworkStateNotifier::NotifyObserversOnTaskRunner(
         observer_list->observers[i]->OnLineStateChange(state.on_line);
         continue;
       case ObserverType::CONNECTION_TYPE:
-        observer_list->observers[i]->ConnectionChange(state.type,
-                                                      state.max_bandwidth_mbps);
+        observer_list->observers[i]->ConnectionChange(
+            state.type, state.max_bandwidth_mbps, state.http_rtt,
+            state.transport_rtt, state.downlink_throughput_mbps);
         continue;
     }
     NOTREACHED();