[Telemetry] Update telemetry_unittests to use tools/perf/run_telemetry_tests

tools/perf/run_telemetry_tests

 #!/usr/bin/env python
-# Copyright 2013 The Chromium Authors. All rights reserved.
+# Copyright 2016 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.
 
 """This script runs unit tests of the code in the perf directory.
 
 This script DOES NOT run benchmarks. run_benchmark does that.
 """
 
 import os
 import subprocess
 import sys
 
 from chrome_telemetry_build import chromium_config
-from core import path_util
 
-sys.path.append(path_util.GetTelemetryDir())
+
+sys.path.append(chromium_config.GetTelemetryDir())
 from telemetry.testing import unittest_runner
 
+
 def main():
-  project_config = chromium_config.ChromiumConfig()
+  project_config = chromium_config.ChromiumConfig(
+      top_level_dir=chromium_config.GetTelemetryDir())
   return unittest_runner.Run(project_config)
 
 if __name__ == '__main__':
   sys.exit(main())