Remove use of deprecated API g_settings_list_schemas

net/proxy/proxy_config_service_linux.cc

Index: net/proxy/proxy_config_service_linux.cc
diff --git a/net/proxy/proxy_config_service_linux.cc b/net/proxy/proxy_config_service_linux.cc
index de41b14f5bffa6a5a38d8716835f0e1457058af8..7db5aa0ac404e867d83082914b06563f4296f6ad 100644
--- a/net/proxy/proxy_config_service_linux.cc
+++ b/net/proxy/proxy_config_service_linux.cc
@@ -547,7 +547,10 @@ class SettingGetterImplGSettings
   }
 
   bool SchemaExists(const char* schema_name) {
-    const gchar* const* schemas = libgio_loader_.g_settings_list_schemas();
+    gchar **schemas = NULL;
+
+    libgio_loader_.g_settings_schema_source_list_schemas(
+        g_settings_schema_source_get_default(), TRUE, &schemas, NULL);
     while (*schemas) {
       if (strcmp(schema_name, static_cast<const char*>(*schemas)) == 0)
         return true;