Make run_isolated_script_test.py work with retries

Bug: 533481
Change-Id: I0ff00a6aeb20853d26f83b893e0eab1c1fa46b48
Reviewed-on: https://chromium-review.googlesource.com/1100295Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Commit-Queue: Stephen Martinis <martiniss@chromium.org>
Cr-Commit-Position: refs/heads/master@{#567827}

testing/scripts/run_isolated_script_test.py

@@ -73,7 +73,11 @@ def main():
       temp_filter_file = tempfile.NamedTemporaryFile(mode='w', delete=False)
       temp_filter_file.write('\n'.join(filter_list))
       temp_filter_file.close()
-      cmd += ['--test-list=' + temp_filter_file.name]
+      arg_name = 'test-list'
+      for arg in rest_args:
+        if 'run_blinkpy_tests.py' in arg:
+          arg_name = 'file-list'
+      cmd += ['--%s=' % arg_name + temp_filter_file.name]
     if args.xvfb:
       return xvfb.run_executable(cmd, env)
     else: