Split generated libraries out of //build/linux

build/linux/libgio/BUILD.gn

+# Copyright (c) 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.
+
+import("//tools/generate_library_loader/generate_library_loader.gni")
+
+gypi_values = exec_script("//build/gypi_to_gn.py",
+                          [ rebase_path("../system.gyp") ],
+                          "scope",
+                          [ "../system.gyp" ])
+
+# This generates a target named "gio".
+generate_library_loader("gio") {
+  name = "LibGioLoader"
+  output_h = "libgio.h"
+  output_cc = "libgio_loader.cc"
+  header = "<gio/gio.h>"
+  config = "//build/linux:gio_config"
+
+  functions = gypi_values.libgio_functions
+}