[Findit] Refactoring compile recipe return results into report dict instead of list

scripts/slave/recipes/findit/chromium/compile.py

Index: scripts/slave/recipes/findit/chromium/compile.py
diff --git a/scripts/slave/recipes/findit/chromium/compile.py b/scripts/slave/recipes/findit/chromium/compile.py
index ef3a929ca8c3fb03ba89949f96645f978e2b3738..60ee6ebb7d2b5bddd3ef6a2de3186216ed7fa6c2 100644
--- a/scripts/slave/recipes/findit/chromium/compile.py
+++ b/scripts/slave/recipes/findit/chromium/compile.py
@@ -10,15 +10,15 @@ from recipe_engine.recipe_api import Property
 
 
 DEPS = [
-  'chromium',
-  'chromium_tests',
-  'findit',
-  'gclient',
-  'recipe_engine/json',
-  'recipe_engine/path',
-  'recipe_engine/properties',
-  'recipe_engine/python',
-  'recipe_engine/step',
+    'chromium',
+    'chromium_tests',
+    'findit',
+    'gclient',
+    'recipe_engine/json',
+    'recipe_engine/path',
+    'recipe_engine/properties',
+    'recipe_engine/python',
+    'recipe_engine/step',
 ]
 
 
@@ -52,10 +52,8 @@ def _run_compile_at_revision(api, target_mastername, target_buildername,
     # Checkout code at the given revision to recompile.
     bot_config = api.chromium_tests.create_bot_config_object(
         target_mastername, target_buildername)
-    bot_update_step, bot_db = \
-        api.chromium_tests.prepare_checkout(
-            bot_config,
-            root_solution_revision=revision)
+    bot_update_step, bot_db = api.chromium_tests.prepare_checkout(
+        bot_config, root_solution_revision=revision)
 
     # TODO(http://crbug.com/560991): if compile targets are provided, check
     # whether they exist and then use analyze to compile the impacted ones by
@@ -114,34 +112,48 @@ def RunSteps(api, target_mastername, target_buildername,
       root_solution_revision=bad_revision)
   revisions_to_check = api.findit.revisions_between(good_revision, bad_revision)
 
-  results = []
+  compile_results = {}
+  try_job_metadata = {
+      'regression_range_size': len(revisions_to_check)
+  }
+  report = {
+      'result': compile_results,
+      'metadata': try_job_metadata,
+  }
+
   try:
     for current_revision in revisions_to_check:
+      last_revision = None
       compile_result = _run_compile_at_revision(
           api, target_mastername, target_buildername,
           current_revision, requested_compile_targets, use_analyze)
 
-      results.append([current_revision, compile_result])
+      compile_results[current_revision] = compile_result
+      last_revision = current_revision
       if compile_result == CompileResult.FAILED:
         # TODO(http://crbug.com/560991): if compile targets are specified,
         # compile may fail because those targets are added in a later revision.
-        break # Found the culprit, no need to check later revisions.
+        break  # Found the culprit, no need to check later revisions.
   finally:
     # Report the result.
     # TODO(http://crbug.com/563807): use api.python.succeeding_step instead.
     step_result = api.python.inline(
         'report', 'import sys; sys.exit(0)', add_python_log=False)
+
     if (not requested_compile_targets and
-        results and results[-1][1] == CompileResult.FAILED):
-      step_result.presentation.step_text = '<br/>Culprit: %s' % results[-1][0]
+        compile_results and
+        last_revision and
+        compile_results.get(last_revision) == CompileResult.FAILED):
+      step_result.presentation.step_text = '<br/>Culprit: %s' % last_revision
+
     step_result.presentation.logs.setdefault('result', []).append(
-        json.dumps(results, indent=2))
+        json.dumps(report, indent=2))
 
     # Set the result as a build property too, so that it will be reported back
     # to Buildbucket and Findit will pull from there instead of buildbot master.
-    step_result.presentation.properties['result'] = results
+    step_result.presentation.properties['result'] = report
 
-  return results
+  return report
 
 
 def GenTests(api):
@@ -171,11 +183,11 @@ def GenTests(api):
       props() +
       api.override_step_data('test r1.read test spec',
                              api.json.output({
-                                'Linux Builder': {
-                                   'additional_compile_targets': [
-                                       'base_unittests',
-                                   ],
-                                }
+                                 'Linux Builder': {
+                                     'additional_compile_targets': [
+                                         'base_unittests',
+                                     ],
+                                 }
                              }))
   )
 
@@ -226,12 +238,12 @@ def GenTests(api):
       props(use_analyze=True) +
       api.override_step_data('test r1.read test spec',
                              api.json.output({
-                                'Linux Builder': {
-                                   'additional_compile_targets': [
-                                       'a', 'a_run',
-                                       'b', 'b_run',
-                                   ],
-                                }
+                                 'Linux Builder': {
+                                     'additional_compile_targets': [
+                                         'a', 'a_run',
+                                         'b', 'b_run',
+                                     ],
+                                 }
                              })) +
       api.override_step_data(
           'test r1.analyze',