Wrap devtoolslib doctests in a unittest so that the test runner sees them.

mojo/devtools/common/devtoolslib/doctests_unittest.py

Index: mojo/devtools/common/devtoolslib/doctests_unittest.py
diff --git a/mojo/devtools/common/devtoolslib/doctests_unittest.py b/mojo/devtools/common/devtoolslib/doctests_unittest.py
new file mode 100644
index 0000000000000000000000000000000000000000..63b63f6b1fd75df05d1b0ff3f356adbbb20eb278
--- /dev/null
+++ b/mojo/devtools/common/devtoolslib/doctests_unittest.py
@@ -0,0 +1,15 @@
+# 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.
+
+"""Wraps the doctests in devtoolslib in a unittest, so that they are picked up
+by our Python test runner."""
+
+import doctest
+from devtoolslib import shell_arguments
+
+
+def load_tests(loader, tests, pattern):
+  del loader, pattern  # Unused.
+  tests.addTests(doctest.DocTestSuite(shell_arguments))
+  return tests