Add NetworkChangeNotifier::ConnectionType to SystemProfile.

chrome/browser/metrics/metrics_log.h

Index: chrome/browser/metrics/metrics_log.h
diff --git a/chrome/browser/metrics/metrics_log.h b/chrome/browser/metrics/metrics_log.h
index df6a3b533bcaf43affee02c8d2a8b0e7169e6c1f..4d9565063fba40bcd3b8aed8823787e0483b7691 100644
--- a/chrome/browser/metrics/metrics_log.h
+++ b/chrome/browser/metrics/metrics_log.h
@@ -141,6 +141,8 @@ class MetricsLog : public MetricsLogBase {
  private:
   FRIEND_TEST_ALL_PREFIXES(MetricsLogTest, ChromeOSStabilityData);
 
+  class NetworkObserver;
+
   // Writes application stability metrics (as part of the profile log).
   // NOTE: Has the side-effect of clearing those counts.
   void WriteStabilityElement(
@@ -184,6 +186,10 @@ class MetricsLog : public MetricsLogBase {
   // This is a no-op if called on a non-Windows platform.
   void WriteGoogleUpdateProto(const GoogleUpdateMetrics& google_update_metrics);
 
+  // Registers as observer with net::NetworkChangeNotifier and keeps track of
+  // the network environment.
+  scoped_ptr<NetworkObserver> network_observer_;
+
   DISALLOW_COPY_AND_ASSIGN(MetricsLog);
 };