Add Observatory mojo_shell hearbeat test

mojo/dart/observatory_tester/runner.py

+#!/usr/bin/python
+# Copyright 2015 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 the Observatory tests in the mojo tree."""
+
+import argparse
+import os
+import subprocess
+import sys
+
+MOJO_SHELL = 'mojo_shell'
+TESTEE = 'mojo:observatory_test'
+
+def main(build_dir, dart_exe, tester_script):
+  shell_exe = os.path.join(build_dir, MOJO_SHELL)
+  subprocess.check_call([
+    dart_exe,
+    tester_script,
+    shell_exe,
+    TESTEE
+  ])
+
+if __name__ == '__main__':
+  parser = argparse.ArgumentParser(
+      description="List filenames of files in the packages/ subdir of the "
+                  "given directory.")
+  parser.add_argument("--build-dir",
+                      dest="build_dir",
+                      metavar="<build-directory>",
+                      type=str,
+                      required=True,
+                      help="The directory containing mojo_shell.")
+  parser.add_argument("--dart-exe",
+                      dest="dart_exe",
+                      metavar="<package-name>",
+                      type=str,
+                      required=True,
+                      help="Path to dart executable.")
+  args = parser.parse_args()
+  tester_dir = os.path.dirname(os.path.realpath(__file__))
+  tester_dart_script = os.path.join(tester_dir, 'tester.dart');
+  sys.exit(main(args.build_dir, args.dart_exe, tester_dart_script))