diagnose_goma show summary as step text.

scripts/slave/recipe_modules/chromium_tests/steps.py

Index: scripts/slave/recipe_modules/chromium_tests/steps.py
diff --git a/scripts/slave/recipe_modules/chromium_tests/steps.py b/scripts/slave/recipe_modules/chromium_tests/steps.py
index 58a0fe05541d442aced7a19dbf692e56be6f31d0..57c91540e5bdbee5d21a9eca4ae17361015cfec0 100644
--- a/scripts/slave/recipe_modules/chromium_tests/steps.py
+++ b/scripts/slave/recipe_modules/chromium_tests/steps.py
@@ -1843,7 +1843,18 @@ class DiagnoseGomaTest(Test):
   def run(self, api, suffix, test_filter=None):
     diagnose_goma_log_py = api.path['build'].join('goma',
                                                   'diagnose_goma_log.py')
-    api.python('diagnose_goma', diagnose_goma_log_py, [])
+    api.python('diagnose_goma', diagnose_goma_log_py,
+               ['--output-json', api.json.output()])
+    step_result = api.step.active_result
+    out_json = step_result.json
+    text_output = [
+        'version %(goma_version)s, commit %(goma_revision)s' % output_json,
+        'Fatal %(fatal)d, Error %(error)d, Warning %(warning)d' %
+        output_json['stats']
+    ]
+    text_output.extend(out_json['messages'])
+    step_result.presentation.step_text += api.test_utils.format_step_text(
+        text_output)
 
 
 class IncrementalCoverageTest(Test):