Remove MetricsServiceObserver in favor of MetricsProvider.

chrome/browser/metrics/network_metrics_provider.cc

Index: chrome/browser/metrics/network_metrics_provider.cc
diff --git a/chrome/browser/metrics/network_metrics_provider.cc b/chrome/browser/metrics/network_metrics_provider.cc
index b039889973c470822d06454fe7c228ec1640c9cf..d540b63fd41f58d0ab308500d60fab704a1ef6a6 100644
--- a/chrome/browser/metrics/network_metrics_provider.cc
+++ b/chrome/browser/metrics/network_metrics_provider.cc
@@ -4,6 +4,9 @@
 
 #include "chrome/browser/metrics/network_metrics_provider.h"
 
+#include <string>
+#include <vector>
+
 #include "base/compiler_specific.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_split.h"
@@ -32,6 +35,11 @@ NetworkMetricsProvider::~NetworkMetricsProvider() {
   net::NetworkChangeNotifier::RemoveConnectionTypeObserver(this);
 }
 
+void NetworkMetricsProvider::OnDidCreateMetricsLog() {
+  net::NetworkChangeNotifier::LogOperatorCodeHistogram(
+      net::NetworkChangeNotifier::GetConnectionType());
+}
+
 void NetworkMetricsProvider::ProvideSystemProfileMetrics(
     SystemProfileProto* system_profile) {
   SystemProfileProto::Network* network = system_profile->mutable_network();