Update from https://crrev.com/303153

build/android/pylib/base/test_instance.py

Index: build/android/pylib/base/test_instance.py
diff --git a/build/android/pylib/base/test_instance.py b/build/android/pylib/base/test_instance.py
new file mode 100644
index 0000000000000000000000000000000000000000..cdf678f2d287b1efcad2f05e91ab9f8a1057c727
--- /dev/null
+++ b/build/android/pylib/base/test_instance.py
@@ -0,0 +1,35 @@
+# 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.
+
+
+class TestInstance(object):
+  """A type of test.
+
+  This is expected to handle all logic that is test-type specific but
+  independent of the environment or device.
+
+  Examples include:
+    - gtests
+    - instrumentation tests
+  """
+
+  def __init__(self):
+    pass
+
+  def TestType(self):
+    raise NotImplementedError
+
+  def SetUp(self):
+    raise NotImplementedError
+
+  def TearDown(self):
+    raise NotImplementedError
+
+  def __enter__(self):
+    self.SetUp()
+    return self
+
+  def __exit__(self, _exc_type, _exc_val, _exc_tb):
+    self.TearDown()
+