Track sources of proxy settings.

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 d57088d09948aacfc0185df66223cb6225428acc..e85dc542fbb0c4f1a626abd50ab9e99d5e174d0a 100644
--- a/net/proxy/proxy_config_service_win.cc
+++ b/net/proxy/proxy_config_service_win.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Copyright (c) 2012 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.
 
@@ -187,6 +187,7 @@ void ProxyConfigServiceWin::SetFromIEConfig(
   }
   if (ie_config.lpszAutoConfigUrl)
     config->set_pac_url(GURL(ie_config.lpszAutoConfigUrl));
+  config->set_source(PROXY_CONFIG_SOURCE_SYSTEM);
 }
 
 }  // namespace net