Move onc and proxy pref names to components.

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
index 9e65ad6e11e5b7777a727a209f22b71d6416f0d5..bee806a223efbb69a24f2d4afbc98c745058fb2a 100644
--- a/components/proxy_config/proxy_config_pref_names.cc
+++ b/components/proxy_config/proxy_config_pref_names.cc
@@ -10,6 +10,9 @@ namespace prefs {
 // Preference to store proxy settings.
 const char kProxy[] = "proxy";
 
+// A boolean pref that controls whether proxy settings from shared network
+// settings (accordingly from device policy) are applied or ignored.
+const char kUseSharedProxies[] = "settings.use_shared_proxies";
+
 }  // namespace prefs
 }  // namespace proxy_config
-