Remove content::NotificationObserver dependency from most Prefs code.

chrome/browser/chromeos/proxy_config_service_impl.cc

Index: chrome/browser/chromeos/proxy_config_service_impl.cc
diff --git a/chrome/browser/chromeos/proxy_config_service_impl.cc b/chrome/browser/chromeos/proxy_config_service_impl.cc
index 03228db25d8021faa523e7b5d9f7ced8f85d7fa1..f9021f02a985ebc33e3163058fdfde7e72a8d848 100644
--- a/chrome/browser/chromeos/proxy_config_service_impl.cc
+++ b/chrome/browser/chromeos/proxy_config_service_impl.cc
@@ -572,29 +572,22 @@ void ProxyConfigServiceImpl::RegisterPrefs(PrefService* pref_service) {
 
 //------------------ ProxyConfigServiceImpl: private methods -------------------
 
-void ProxyConfigServiceImpl::Observe(
-    int type,
-    const content::NotificationSource& source,
-    const content::NotificationDetails& details) {
-  if (type == chrome::NOTIFICATION_PREF_CHANGED &&
-      *(content::Details<std::string>(details).ptr()) ==
-          prefs::kUseSharedProxies) {
-    if (content::Source<PrefService>(source).ptr() == prefs()) {
-      VLOG(1) << "New use-shared-proxies = " << GetUseSharedProxies();
-      // Determine new proxy config which may have changed because of new
-      // use-shared-proxies. If necessary, activate it.
-      Network* network = NULL;
-      if (!active_network_.empty()) {
-        network = CrosLibrary::Get()->GetNetworkLibrary()->FindNetworkByPath(
-            active_network_);
-        if (!network)
-          LOG(WARNING) << "Can't find requested network " << active_network_;
-      }
-      DetermineEffectiveConfig(network, true);
-    }
-    return;
+void ProxyConfigServiceImpl::OnPreferenceChanged(PrefServiceBase* service,
+                                                 const std::string& pref_name) {
+  DCHECK(service == prefs());
+  DCHECK(pref_name == prefs::kUseSharedProxies);
+  VLOG(1) << "New use-shared-proxies = " << GetUseSharedProxies();
+
+  // Determine new proxy config which may have changed because of new
+  // use-shared-proxies. If necessary, activate it.
+  Network* network = NULL;
+  if (!active_network_.empty()) {
+    network = CrosLibrary::Get()->GetNetworkLibrary()->FindNetworkByPath(
+        active_network_);
+    if (!network)
+      LOG(WARNING) << "Can't find requested network " << active_network_;
   }
-  PrefProxyConfigTrackerImpl::Observe(type, source, details);

[Mattias Nissler (ping if slow), 2012/10/31 13:29:35]

I think this breaks, the parent class also needs to observe prefs.

[Jói, 2012/10/31 14:56:26]

You're right, this was caught by a tryjob and is fixed in the newer patch.  It's
interesting that the DCHECK I put on line 578 did not fire though, yet chaining
to the parent class did fix the problem.

+  DetermineEffectiveConfig(network, true);
 }
 
 void ProxyConfigServiceImpl::OnUISetProxyConfig() {