Make unit_tests compile in Mac GN

chrome/browser/apps/app_shim/BUILD.gn

Index: chrome/browser/apps/app_shim/BUILD.gn
diff --git a/chrome/browser/apps/app_shim/BUILD.gn b/chrome/browser/apps/app_shim/BUILD.gn
new file mode 100644
index 0000000000000000000000000000000000000000..78aeb3668cbe44c126ae3e302faac9d07d3fc071
--- /dev/null
+++ b/chrome/browser/apps/app_shim/BUILD.gn
@@ -0,0 +1,27 @@
+# Copyright 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.
+
+# This is the part of the Chrome browser process responsible for launching and
+# communicating with app_shim processes on Mac.
+#
+# GYP version: chrome/browser/apps/app_shim/browser_app_shim.gypi:browser_app_shim
+source_set("app_shim") {
+  sources = [
+    "app_shim_handler_mac.cc",
+    "app_shim_handler_mac.h",
+    "app_shim_host_mac.cc",
+    "app_shim_host_mac.h",
+    "app_shim_host_manager_mac.h",
+    "app_shim_host_manager_mac.mm",
+    "extension_app_shim_handler_mac.cc",
+    "extension_app_shim_handler_mac.h",
+    "unix_domain_socket_acceptor.cc",
+    "unix_domain_socket_acceptor.h",
+  ]
+
+  deps = [
+    "//content/public/browser",
+    "//content/public/common",
+  ]
+}