Added virtualenv for depot_tools

bootstrap/custom_builds/docutils.py

Index: bootstrap/custom_builds/docutils.py
diff --git a/bootstrap/custom_builds/docutils.py b/bootstrap/custom_builds/docutils.py
new file mode 100644
index 0000000000000000000000000000000000000000..9272bc283edfff760d5505ff6addf45ca908d4fe
--- /dev/null
+++ b/bootstrap/custom_builds/docutils.py
@@ -0,0 +1,15 @@
+# Copyright 2014 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.
+
+import os
+import subprocess
+import sys
+
+
+def Build(source_path, wheelhouse_path):
+  assert hasattr(sys, 'real_prefix'), 'virtualenv must be activate'
+  pip_path = os.path.join(sys.prefix, 'bin', 'pip')
+  subprocess.check_call([pip_path, 'wheel', '-w', wheelhouse_path,
+                         '--no-deps', './docutils'],
+    cwd=source_path)