Make the notification builder more XPC friendly

chrome/browser/ui/cocoa/notifications/notification_common.gyp

Index: chrome/browser/ui/cocoa/notifications/notification_common.gyp
diff --git a/chrome/browser/ui/cocoa/notifications/notification_common.gyp b/chrome/browser/ui/cocoa/notifications/notification_common.gyp
new file mode 100644
index 0000000000000000000000000000000000000000..bac5e4bd1681ca7ae186b1414924525a23aeb663
--- /dev/null
+++ b/chrome/browser/ui/cocoa/notifications/notification_common.gyp
@@ -0,0 +1,20 @@
+# 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.
+
+{
+'targets': [
+{
+  # GN version: //chrome/browser/ui/notifications:common
+  'target_name': 'notification_common',
+  'type': 'static_library',
+    'include_dirs': [
+      '<(DEPTH)',
+    ],
+  'sources': [
+    'notification_builder_mac.h',
+    'notification_builder_mac.mm',
+  ],
+},
+],
+}