Expose changes in the network quality to the renderers

content/renderer/render_thread_impl.cc

Index: content/renderer/render_thread_impl.cc
diff --git a/content/renderer/render_thread_impl.cc b/content/renderer/render_thread_impl.cc
index 9dad0206afcd8f05445f0486fe1a066391a0249b..4257028ba1206bc8f08dc7287126dcc7d489db04 100644
--- a/content/renderer/render_thread_impl.cc
+++ b/content/renderer/render_thread_impl.cc
@@ -2129,6 +2129,15 @@ void RenderThreadImpl::OnNetworkConnectionChanged(
       NetConnectionTypeToWebConnectionType(type), max_bandwidth_mbps);
 }
 
+void RenderThreadImpl::OnNetworkQualityChanged(
+    double http_rtt_msec,
+    double transport_rtt_msec,
+    double downlink_throughput_kbps) {
+  UMA_HISTOGRAM_EXACT_LINEAR("NQE.RenderThreadNotified", 1, 2);

[Ilya Sherman, 2017/05/09 21:51:25]

nit: UMA_HISTOGRAM_BOOLEAN("NQE.RenderThreadNotified", true);

[tbansal1, 2017/05/09 23:49:30]

Done. Can you comment a bit on why EXACT_LINEAR is not the right macro here?

[Ilya Sherman, 2017/05/09 23:55:52]

EXACT_LINEAR would be fine as well, I think -- though the final param probably
needs to be 3 rather than 2, as all histograms are expected to have an underflow
and an overflow bucket, plus at least one additional bucket for "real" data. 
Mostly, UMA_HISTOGRAM_BOOLEAN is just less verbose, and hence more readable =)

[tbansal1, 2017/05/10 16:46:42]

Acknowledged.

+  // TODO(tbansal): https://crbug.com/719108. Notify WebNetworkStateNotifier of
+  // the change in the network quality.
+}
+
 void RenderThreadImpl::SetWebKitSharedTimersSuspended(bool suspend) {
 #if defined(OS_ANDROID)
   if (suspend) {