Add a snapshot of flutter/engine/src/build to our sdk

build/android/pylib/pexpect.py

Index: build/android/pylib/pexpect.py
diff --git a/build/android/pylib/pexpect.py b/build/android/pylib/pexpect.py
new file mode 100644
index 0000000000000000000000000000000000000000..cf59fb0f6d368a060ea566d550e1bdd6834e8553
--- /dev/null
+++ b/build/android/pylib/pexpect.py
@@ -0,0 +1,21 @@
+# Copyright (c) 2012 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.
+from __future__ import absolute_import
+
+import os
+import sys
+
+_CHROME_SRC = os.path.join(
+    os.path.abspath(os.path.dirname(__file__)), '..', '..', '..')
+
+_PEXPECT_PATH = os.path.join(_CHROME_SRC, 'third_party', 'pexpect')
+if _PEXPECT_PATH not in sys.path:
+  sys.path.append(_PEXPECT_PATH)
+
+# pexpect is not available on all platforms. We allow this file to be imported
+# on platforms without pexpect and only fail when pexpect is actually used.
+try:
+  from pexpect import * # pylint: disable=W0401,W0614
+except ImportError:
+  pass