Add 'depfile' option to actions.

test/actions-depfile/gyptest-all.py

Index: test/actions-depfile/gyptest-all.py
diff --git a/test/actions-depfile/gyptest-all.py b/test/actions-depfile/gyptest-all.py
new file mode 100644
index 0000000000000000000000000000000000000000..23f6f4a056707b79995973e9c27ddaf01a26fd3b
--- /dev/null
+++ b/test/actions-depfile/gyptest-all.py
@@ -0,0 +1,20 @@
+#!/usr/bin/env python
+
+# Copyright (c) 2014 Google Inc. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""Verifies that depfile fields are output in ninja rules."""
+
+import TestGyp
+
+test = TestGyp.TestGyp()
+
+if test.format == 'ninja':
+  test.run_gyp('depfile.gyp')
+  contents = open(test.built_file_path('obj/depfile_target.ninja')).read()
+
+  expected = 'depfile = depfile.d'
+  if expected not in contents:
+    test.fail_test()
+  test.pass_test()