Bundle resources and skps directories into iOS app.

Will bundle resources/ for viewer (and skps/ if
that directory exists in the main Skia directory).
Also updates file code on iOS to fall back to bundle directory.

Docs-Preview: https://skia.org/?cl=76803
Bug: skia:7339
Change-Id: I244f67559c866451a6d02c3f1c4948d89457ec84
Reviewed-on: https://skia-review.googlesource.com/76803
Commit-Queue: Jim Van Verth <jvanverth@google.com>
Reviewed-by: Mike Klein <mtklein@chromium.org>
diff --git a/gn/checkdir.py b/gn/checkdir.py
new file mode 100644
index 0000000..4de7e80
--- /dev/null
+++ b/gn/checkdir.py
@@ -0,0 +1,15 @@
+#!/usr/bin/env python
+#
+# Copyright 2017 Google Inc.
+#
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import os
+import sys
+
+dirpath, = sys.argv[1:]
+
+print os.path.isdir(dirpath)
+
+