Refactor stages 1, 2 and test_api overhaul.

scripts/slave/recipe_modules/perf_try/api.py

Index: scripts/slave/recipe_modules/perf_try/api.py
diff --git a/scripts/slave/recipe_modules/perf_try/api.py b/scripts/slave/recipe_modules/perf_try/api.py
index b6a2c8d35cec69c02587133c358585a58b9a83aa..a5fb634a6cfe23eb3f5b045fdbab0fbd05022775 100644
--- a/scripts/slave/recipe_modules/perf_try/api.py
+++ b/scripts/slave/recipe_modules/perf_try/api.py
@@ -177,17 +177,17 @@ class PerfTryJobApi(recipe_api.RecipeApi):
 
   def _run_test(self, cfg, **kwargs):
     """Runs test from config and return results."""
-    values, overall_output, retcodes = self.m.bisect_tester.run_test(
+    run_results = self.m.bisect_tester.run_test(
         cfg, **kwargs)
-    all_values = self.m.bisect_tester.digest_run_results(values, retcodes, cfg)
+    all_values = self.m.bisect_tester.digest_run_results(run_results, cfg)
     overall_success = True
     if (not kwargs.get('allow_flakes', True) and
         cfg.get('test_type', 'perf') != 'return_code'):
-      overall_success = all(v == 0 for v in retcodes)
+      overall_success = all(v == 0 for v in run_results['retcodes'])
     return {
         'results': all_values,
         'ret_code': overall_success,
-        'output': ''.join(overall_output)
+        'output': ''.join(run_results['output'])
     }
 
   def _build_and_run_tests(self, cfg, update_step, bot_db, revision_hash,