Add coverage

tools/telemetry/third_party/coverage/coverage/backunittest.py

Index: tools/telemetry/third_party/coverage/coverage/backunittest.py
diff --git a/tools/telemetry/third_party/coverage/coverage/backunittest.py b/tools/telemetry/third_party/coverage/coverage/backunittest.py
new file mode 100644
index 0000000000000000000000000000000000000000..09574ccb61d1e53d2fe2abf7fb0bc5cf3c1d8207
--- /dev/null
+++ b/tools/telemetry/third_party/coverage/coverage/backunittest.py
@@ -0,0 +1,42 @@
+# Licensed under the Apache License: http://www.apache.org/licenses/LICENSE-2.0
+# For details: https://bitbucket.org/ned/coveragepy/src/default/NOTICE.txt
+
+"""Implementations of unittest features from the future."""
+
+# Use unittest2 if it's available, otherwise unittest.  This gives us
+# back-ported features for 2.6.
+try:
+    import unittest2 as unittest
+except ImportError:
+    import unittest
+
+
+def unittest_has(method):
+    """Does `unittest.TestCase` have `method` defined?"""
+    return hasattr(unittest.TestCase, method)
+
+
+class TestCase(unittest.TestCase):
+    """Just like unittest.TestCase, but with assert methods added.
+
+    Designed to be compatible with 3.1 unittest.  Methods are only defined if
+    `unittest` doesn't have them.
+
+    """
+    # pylint: disable=missing-docstring
+
+    # Many Pythons have this method defined.  But PyPy3 has a bug with it
+    # somehow (https://bitbucket.org/pypy/pypy/issues/2092), so always use our
+    # own implementation that works everywhere, at least for the ways we're
+    # calling it.
+    def assertCountEqual(self, s1, s2):
+        """Assert these have the same elements, regardless of order."""
+        self.assertEqual(sorted(s1), sorted(s2))
+
+    if not unittest_has('assertRaisesRegex'):
+        def assertRaisesRegex(self, *args, **kwargs):
+            return self.assertRaisesRegexp(*args, **kwargs)
+
+    if not unittest_has('assertRegex'):
+        def assertRegex(self, *args, **kwargs):
+            return self.assertRegexpMatches(*args, **kwargs)