Add in-memory caching of network quality estimates across network changes.

net/base/network_quality.cc

Index: net/base/network_quality.cc
diff --git a/net/base/network_quality.cc b/net/base/network_quality.cc
index a1a1ee04a1b2b0da88258fb99e0060fd72bce00e..cb75f3df7b36bbb8703cebe92280850cce4b38e5 100644
--- a/net/base/network_quality.cc
+++ b/net/base/network_quality.cc
@@ -15,6 +15,17 @@ NetworkQuality::NetworkQuality(const base::TimeDelta& rtt,
   DCHECK_GE(downstream_throughput_kbps_, 0);
 }
 
+NetworkQuality::NetworkQuality(const NetworkQuality& other)
+    : rtt_(other.rtt_),
+      downstream_throughput_kbps_(other.downstream_throughput_kbps_) {
+}
+
+NetworkQuality& NetworkQuality::operator=(const NetworkQuality& other) {
+  rtt_ = other.rtt_;
+  downstream_throughput_kbps_ = other.downstream_throughput_kbps_;
+  return *this;
+}
+
 NetworkQuality::~NetworkQuality() {
 }