Revert 99677 (didn't help) - Revert 99666 (sync tests started failing on mac10.6:

net/base/network_change_notifier.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/base/network_change_notifier.h"
 #include "net/base/network_change_notifier_factory.h"
 #include "build/build_config.h"
 #if defined(OS_WIN)
 #include "net/base/network_change_notifier_win.h"
 #elif defined(OS_LINUX) || defined(OS_ANDROID)
@@ skipping 72 matching lines @@
 }
 
 void NetworkChangeNotifier::AddOnlineStateObserver(
     OnlineStateObserver* observer) {
   if (g_network_change_notifier) {
     g_network_change_notifier->online_state_observer_list_->AddObserver(
         observer);
   }
 }
 
+void NetworkChangeNotifier::AddDNSObserver(DNSObserver* observer) {
+  if (g_network_change_notifier) {
+    g_network_change_notifier->resolver_state_observer_list_->AddObserver(
+        observer);
+  }
+}
+
 void NetworkChangeNotifier::RemoveIPAddressObserver(
     IPAddressObserver* observer) {
   if (g_network_change_notifier) {
     g_network_change_notifier->ip_address_observer_list_->RemoveObserver(
         observer);
   }
 }
 
 void NetworkChangeNotifier::RemoveOnlineStateObserver(
     OnlineStateObserver* observer) {
   if (g_network_change_notifier) {
     g_network_change_notifier->online_state_observer_list_->RemoveObserver(
         observer);
   }
 }
 
+void NetworkChangeNotifier::RemoveDNSObserver(DNSObserver* observer) {
+  if (g_network_change_notifier) {
+    g_network_change_notifier->resolver_state_observer_list_->RemoveObserver(
+        observer);
+  }
+}
+
 NetworkChangeNotifier::NetworkChangeNotifier()
     : ip_address_observer_list_(
         new ObserverListThreadSafe<IPAddressObserver>(
             ObserverListBase<IPAddressObserver>::NOTIFY_EXISTING_ONLY)),
       online_state_observer_list_(
         new ObserverListThreadSafe<OnlineStateObserver>(
-            ObserverListBase<OnlineStateObserver>::NOTIFY_EXISTING_ONLY)) {
+            ObserverListBase<OnlineStateObserver>::NOTIFY_EXISTING_ONLY)),
+      resolver_state_observer_list_(
+        new ObserverListThreadSafe<DNSObserver>(
+            ObserverListBase<DNSObserver>::NOTIFY_EXISTING_ONLY)) {
   DCHECK(!g_network_change_notifier);
   g_network_change_notifier = this;
 }
 
 void NetworkChangeNotifier::NotifyObserversOfIPAddressChange() {
   if (g_network_change_notifier) {
     g_network_change_notifier->ip_address_observer_list_->Notify(
         &IPAddressObserver::OnIPAddressChanged);
   }
 }
 
+void NetworkChangeNotifier::NotifyObserversOfDNSChange() {
+  if (g_network_change_notifier) {
+    g_network_change_notifier->resolver_state_observer_list_->Notify(
+        &DNSObserver::OnDNSChanged);
+  }
+}
+
 void NetworkChangeNotifier::NotifyObserversOfOnlineStateChange() {
   if (g_network_change_notifier) {
     g_network_change_notifier->online_state_observer_list_->Notify(
         &OnlineStateObserver::OnOnlineStateChanged, !IsOffline());
   }
 }
 
 }  // namespace net