Expose RTT and throughput estimates from Cronet

net/nqe/network_quality.cc

Index: net/nqe/network_quality.cc
diff --git a/net/nqe/network_quality.cc b/net/nqe/network_quality.cc
index 6831dd4b2135ed838cee6d8bda37f2007ff0b1c0..6c572dc917d9b3a1157f4950393a10edcd7129cd 100644
--- a/net/nqe/network_quality.cc
+++ b/net/nqe/network_quality.cc
@@ -9,7 +9,7 @@ namespace nqe {
 namespace internal {
 
 base::TimeDelta InvalidRTT() {
-  return base::TimeDelta::Max();
+  return base::TimeDelta::FromMilliseconds(INVALID_RTT_THROUGHPUT);
 }
 
 NetworkQuality::NetworkQuality()
@@ -21,7 +21,7 @@ NetworkQuality::NetworkQuality(const base::TimeDelta& http_rtt,
     : http_rtt_(http_rtt),
       transport_rtt_(transport_rtt),
       downstream_throughput_kbps_(downstream_throughput_kbps) {
-  DCHECK_GE(downstream_throughput_kbps_, 0);
+  DCHECK_GE(downstream_throughput_kbps_, kInvalidThroughput);
 }
 
 NetworkQuality::NetworkQuality(const NetworkQuality& other)