Add NetworkChangeNotifier connectivity events to the NetLog.

chrome/browser/io_thread.cc

Index: chrome/browser/io_thread.cc
diff --git a/chrome/browser/io_thread.cc b/chrome/browser/io_thread.cc
index 08ed80c0562ac423e339c5c43af3ed34bd55f5b2..5ae0edbc224d739d922cc4d9f5ff937c237967e3 100644
--- a/chrome/browser/io_thread.cc
+++ b/chrome/browser/io_thread.cc
@@ -244,16 +244,19 @@ ConstructSystemRequestContext(IOThread::Globals* globals,
 }  // namespace
 
 class IOThread::LoggingNetworkChangeObserver
-    : public net::NetworkChangeNotifier::IPAddressObserver {
+    : public net::NetworkChangeNotifier::IPAddressObserver,
+      public net::NetworkChangeNotifier::ConnectionTypeObserver {
  public:
   // |net_log| must remain valid throughout our lifetime.
   explicit LoggingNetworkChangeObserver(net::NetLog* net_log)
       : net_log_(net_log) {
     net::NetworkChangeNotifier::AddIPAddressObserver(this);
+    net::NetworkChangeNotifier::AddConnectionTypeObserver(this);
   }
 
   ~LoggingNetworkChangeObserver() {
     net::NetworkChangeNotifier::RemoveIPAddressObserver(this);
+    net::NetworkChangeNotifier::RemoveConnectionTypeObserver(this);
   }
 
   virtual void OnIPAddressChanged() {
@@ -262,6 +265,19 @@ class IOThread::LoggingNetworkChangeObserver
     net_log_->AddGlobalEntry(net::NetLog::TYPE_NETWORK_IP_ADDRESSES_CHANGED);
   }
 
+  virtual void OnConnectionTypeChanged(

[mmenke, 2012/10/25 16:25:31]

While you're here, could you make this and OnIPAddressChanged both OVERRIDE? 
Thanks.

+      net::NetworkChangeNotifier::ConnectionType type) {
+    std::string type_as_string =
+        net::NetworkChangeNotifier::ConnectionTypeToString(type);
+
+    VLOG(1) << "Observed a change to network connectivity state "
+            << type_as_string;
+
+    net_log_->AddGlobalEntry(
+        net::NetLog::TYPE_NETWORK_CONNECTIVITY_CHANGED,
+        net::NetLog::StringCallback("new_type", &type_as_string));
+  }
+
  private:
   net::NetLog* net_log_;
   DISALLOW_COPY_AND_ASSIGN(LoggingNetworkChangeObserver);