Componentize proxy code from chrome/browser/net

components/proxy_config/proxy_config_pref_names.cc

Index: components/proxy_config/proxy_config_pref_names.cc
diff --git a/components/proxy_config/proxy_config_pref_names.cc b/components/proxy_config/proxy_config_pref_names.cc
new file mode 100644
index 0000000000000000000000000000000000000000..9e65ad6e11e5b7777a727a209f22b71d6416f0d5
--- /dev/null
+++ b/components/proxy_config/proxy_config_pref_names.cc
@@ -0,0 +1,15 @@
+// Copyright 2015 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 "components/proxy_config/proxy_config_pref_names.h"
+
+namespace proxy_config {
+namespace prefs {
+
+// Preference to store proxy settings.
+const char kProxy[] = "proxy";
+
+}  // namespace prefs
+}  // namespace proxy_config
+