Change test_util summarize_retried_test not to use inline python

scripts/slave/recipes/blink_downstream.expected/minimal_pass_continues.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "[BUILD]/scripts/slave/bot_update.py",
       "--master",
       "client.v8.fyi",
       "--builder",
       "V8-Blink Linux 64",
@@ skipping 297 matching lines @@
     "cwd": "[SLAVE_BUILD]",
     "name": "webkit_tests (without patch)",
     "~followup_annotations": [
       "@@@STEP_TEXT@<br/>Total executed: 9001<br/>@@@"
     ]
   },
   {
     "cmd": [
       "python",
       "-u",
-      "\nimport sys, json\nfailures = json.load(open(sys.argv[1], 'rb'))\n\nsuccess = True\n\nif failures['new']:\n  success = False\n  print 'New failures:'\n  for f in failures['new']:\n    print f\n\nif failures['ignored']:\n  print 'Ignored failures:'\n  for f in failures['ignored']:\n    print f\n\nsys.exit(0 if success else 1)\n",
-      "{\"ignored\": [], \"new\": [\"bad/totally-bad-probably.html\", \"tricky/totally-maybe-not-awesome.html\"]}"
+      "import sys; sys.exit(1)"
     ],
     "cwd": "[SLAVE_BUILD]",
     "name": "webkit_tests",
     "~followup_annotations": [
+      "step returned non-zero exit code: 1",
       "@@@STEP_TEXT@<br/>failures:<br/>bad/totally-bad-probably.html<br/>tricky/totally-maybe-not-awesome.html<br/>@@@",
-      "@@@STEP_LOG_LINE@python.inline@@@@",
-      "@@@STEP_LOG_LINE@python.inline@import sys, json@@@",
-      "@@@STEP_LOG_LINE@python.inline@failures = json.load(open(sys.argv[1], 'rb'))@@@",
-      "@@@STEP_LOG_LINE@python.inline@@@@",
-      "@@@STEP_LOG_LINE@python.inline@success = True@@@",
-      "@@@STEP_LOG_LINE@python.inline@@@@",
-      "@@@STEP_LOG_LINE@python.inline@if failures['new']:@@@",
-      "@@@STEP_LOG_LINE@python.inline@  success = False@@@",
-      "@@@STEP_LOG_LINE@python.inline@  print 'New failures:'@@@",
-      "@@@STEP_LOG_LINE@python.inline@  for f in failures['new']:@@@",
-      "@@@STEP_LOG_LINE@python.inline@    print f@@@",
-      "@@@STEP_LOG_LINE@python.inline@@@@",
-      "@@@STEP_LOG_LINE@python.inline@if failures['ignored']:@@@",
-      "@@@STEP_LOG_LINE@python.inline@  print 'Ignored failures:'@@@",
-      "@@@STEP_LOG_LINE@python.inline@  for f in failures['ignored']:@@@",
-      "@@@STEP_LOG_LINE@python.inline@    print f@@@",
-      "@@@STEP_LOG_LINE@python.inline@@@@",
-      "@@@STEP_LOG_LINE@python.inline@sys.exit(0 if success else 1)@@@",
-      "@@@STEP_LOG_END@python.inline@@@",
       "@@@STEP_FAILURE@@@"
     ]
+  },
+  {
+    "name": "$final_result",
+    "reason": "1 out of 1 aggregated steps failed. Failures: Step('webkit_tests') failed with return_code 1",
+    "status_code": 1
   }
 ]