[Mac/GN] Add BUILD.gn file for //chrome/tools/mac_helpers.

chrome/tools/mac_helpers/BUILD.gn

Index: chrome/tools/mac_helpers/BUILD.gn
diff --git a/chrome/tools/mac_helpers/BUILD.gn b/chrome/tools/mac_helpers/BUILD.gn
new file mode 100644
index 0000000000000000000000000000000000000000..801ccda996df88df4fe640d2843a64f884dce64b
--- /dev/null
+++ b/chrome/tools/mac_helpers/BUILD.gn
@@ -0,0 +1,19 @@
+# Copyright 2016 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.
+
+executable("infoplist_strings_tool") {
+  configs += [ "//build/config/compiler:wexit_time_destructors" ]
+
+  sources = [
+    "infoplist_strings_util.mm",
+  ]
+
+  deps = [
+    "//base",
+    "//chrome:strings",
+    "//ui/base:ui_data_pack",
+  ]
+
+  libs = [ "Foundation.framework" ]
+}