Allow ProxyConfigService to report "no configuration set"

net/proxy/proxy_config_service_win.h

Index: net/proxy/proxy_config_service_win.h
diff --git a/net/proxy/proxy_config_service_win.h b/net/proxy/proxy_config_service_win.h
index dc1da121ff5dbe67af7a8d0674f0c31fafb912ff..1184ef3e954500323ba26341f97df92460848e1d 100644
--- a/net/proxy/proxy_config_service_win.h
+++ b/net/proxy/proxy_config_service_win.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -64,7 +64,7 @@ class ProxyConfigServiceWin : public PollingProxyConfigService,
   // This is called whenever one of the registry keys we are watching change.
   virtual void OnObjectSignaled(HANDLE object);
 
-  static void GetCurrentProxyConfig(ProxyConfig* config);
+  static ConfigAvailability GetCurrentProxyConfig(ProxyConfig* config);
 
   // Set |config| using the proxy configuration values of |ie_config|.
   static void SetFromIEConfig(