metrics_python_tests: Pass correct filter argument

Makes the isolated script test wrapper script know that
metrics_python_tests is a typ based test suite, so that it passes the
proper command line argument to it.

Bug: 533481
Change-Id: Ifd45f947409989174e1da046be6a8342931f82eb
Reviewed-on: https://chromium-review.googlesource.com/1109400Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Reviewed-by: Kenneth Russell <kbr@chromium.org>
Commit-Queue: Stephen Martinis <martiniss@chromium.org>
Cr-Commit-Position: refs/heads/master@{#569423}

testing/scripts/run_isolated_script_test.py

@@ -46,6 +46,12 @@ sys.path.append(os.path.join(os.path.dirname(__file__), '..'))
 import xvfb
 
 
+# Known typ test runners this script wraps. They need a different argument name
+# when selecting which tests to run.
+# TODO(dpranke): Detect if the wrapped test suite uses typ better.
+KNOWN_TYP_TEST_RUNNERS = ['run_blinkpy_tests.py', 'metrics_python_tests.py']
+
+
 def main():
   parser = argparse.ArgumentParser()
   parser.add_argument('--isolated-script-test-output', type=str,
@@ -73,10 +79,13 @@ def main():
       temp_filter_file = tempfile.NamedTemporaryFile(mode='w', delete=False)
       temp_filter_file.write('\n'.join(filter_list))
       temp_filter_file.close()
+
       arg_name = 'test-list'
       for arg in rest_args:
-        if 'run_blinkpy_tests.py' in arg:
-          arg_name = 'file-list'
+        for runner in KNOWN_TYP_TEST_RUNNERS:
+          if runner in arg:
+            arg_name = 'file-list'
+
       cmd += ['--%s=' % arg_name + temp_filter_file.name]
     if args.xvfb:
       return xvfb.run_executable(cmd, env)