Allow ProxyConfigService to report "no configuration set"

net/proxy/proxy_config_service_win.cc

Index: net/proxy/proxy_config_service_win.cc
diff --git a/net/proxy/proxy_config_service_win.cc b/net/proxy/proxy_config_service_win.cc
index 3c2fbfff474f7c0fa64649c258f57bb901f50ded..b903a16705ea04523a3d2eed00920491bb64468a 100644
--- a/net/proxy/proxy_config_service_win.cc
+++ b/net/proxy/proxy_config_service_win.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2006-2008 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.
 
@@ -153,16 +153,18 @@ void ProxyConfigServiceWin::OnObjectSignaled(HANDLE object) {
 }
 
 // static
-void ProxyConfigServiceWin::GetCurrentProxyConfig(ProxyConfig* config) {
+ProxyConfigService::ConfigAvailability
+    ProxyConfigServiceWin::GetCurrentProxyConfig(ProxyConfig* config) {
   WINHTTP_CURRENT_USER_IE_PROXY_CONFIG ie_config = {0};
   if (!WinHttpGetIEProxyConfigForCurrentUser(&ie_config)) {
     LOG(ERROR) << "WinHttpGetIEProxyConfigForCurrentUser failed: " <<
         GetLastError();
     *config = ProxyConfig::CreateDirect();
-    return;
+    return CONFIG_UNSET;
   }
   SetFromIEConfig(config, ie_config);
   FreeIEConfig(&ie_config);
+  return CONFIG_VALID;
 }
 
 // static