Add support for module-definition files to gn

build/config/BUILDCONFIG.gn

 # Copyright (c) 2013 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.
 
 if (target_os == "") {
   target_os = host_os
 }
 
 if (target_cpu == "") {
   if (target_os == "android") {
@@ skipping 235 matching lines @@
     "*_posix_unittest.cc",
     "*\bposix/*",
   ]
 }
 if (!is_win) {
   sources_assignment_filter += [
     "*_win.cc",
     "*_win.h",
     "*_win_unittest.cc",
     "*\bwin/*",
+    "*.def",
     "*.rc",
   ]
 }
 if (!is_mac) {
   sources_assignment_filter += [
     "*_mac.h",
     "*_mac.cc",
     "*_mac.mm",
     "*_mac_unittest.h",
     "*_mac_unittest.cc",
@@ skipping 503 matching lines @@
       }
       if (defined(invoker.testonly)) {
         testonly = invoker.testonly
       }
       if (defined(invoker.visibility)) {
         visibility = invoker.visibility
       }
     }
   }
 }