Make test-results upload URL configurable.

scripts/slave/recipe_modules/test_results/api.py

 # 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.
 
 from recipe_engine import recipe_api
 
 
 class TestResultsApi(recipe_api.RecipeApi):
   """Recipe module to upload gtest json results to test-results server."""
 
-  # TODO(estaab): Make test_results_server a configuration value.
   def upload(self, gtest_results_file, test_type, chrome_revision,
-             test_results_server, downgrade_error_to_warning=True):
+             test_results_server=None, downgrade_error_to_warning=True):
     """Upload gtest results json to test-results.
 
     Args:
       gtest_results_file: Path to file containing gtest json.
       test_type: Test type string, e.g. webkit_tests.
       test_results_server: Server where results should be uploaded.
       downgrade_error_to_warning: If True, treat a failure to upload as a
           warning.
 
     Returns:
       The step result.
     """
     try:
-      self.m.python(
+      return self.m.python(
           name='Upload to test-results [%s]' % test_type,
           script=self.resource('upload_gtest_test_results.py'),
           args=['--input-gtest-json', gtest_results_file,
                 '--master-name', self.m.properties['mastername'],
                 '--builder-name', self.m.properties['buildername'],
                 '--build-number', self.m.properties['buildnumber'],
                 '--test-type', test_type,
-                '--test-results-server', test_results_server,
+                '--test-results-server',
+                test_results_server or self.c.test_results_server,
                 '--chrome-revision', chrome_revision])
-    finally:
-      step_result = self.m.step.active_result
-      if (downgrade_error_to_warning and
-          step_result.presentation.status == self.m.step.FAILURE):
-        step_result.presentation.status = self.m.step.WARNING
-      return step_result
-
+    except self.m.step.StepFailure as f:
+      if downgrade_error_to_warning:
+        f.result.presentation.status = self.m.step.WARNING
+      return f.result