Reland of Use the crrev recipe module to fetch commit hashes.

scripts/slave/recipe_modules/auto_bisect/example.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.
 
 import json
 
 DEPS = [
     'auto_bisect',
     'chromium_tests',
     'recipe_engine/json',
@@ skipping 386 matching lines @@
       'skip_gclient_ops': 'True',
       'recipe_tester_name': 'linux_perf_tester'
   }
   if params:
     example_config.update(params)
   return example_config
 
 
 def _get_step_data_for_revision(api, revision_data, include_build_steps=True):
   """Generator that produces step patches for fake results."""
-  commit_pos = revision_data['commit_pos']
+  commit_pos_number = revision_data['commit_pos']
   commit_hash = revision_data['hash']
   test_results = revision_data.get('test_results')
 
   if 'refrange' in revision_data:
     parent_step = 'Resolving reference range.'
-    step_name = parent_step + 'resolving commit_pos ' + commit_pos
-    yield api.step_data(step_name,
-                        stdout=api.raw_io.output('hash:' + commit_hash))
+    commit_pos = 'refs/heads/master@{#%s}' % commit_pos_number
+    step_name = parent_step + 'crrev get commit hash for ' + commit_pos
+    yield api.step_data(
+        step_name,
+        stdout=api.json.output({'git_sha': commit_hash}))
 
   if include_build_steps:
     if test_results:
       step_name = ('Waiting for chromium@%s.gsutil '
                    'Get test results for build %s') % (commit_hash[:10],
                                                        commit_hash)
       yield api.step_data(step_name, stdout=api.json.output(test_results))
 
     if revision_data.get('DEPS', False):
       step_name = 'fetch file %s:DEPS' % commit_hash
@@ skipping 18 matching lines @@
           yield api.step_data(step_name, stdout=api.raw_io.output(file_hash))
         step_name = 'Expanding revision range for revision %s on depot %s'
         step_name %= (interval[-1], depot_name)
         stdout = api.json.output([(r, 0) for r in interval[:-1]])
         yield api.step_data(step_name, stdout=stdout)
 
     if 'cl_info' in revision_data:
       step_name = 'Reading culprit cl information.'
       stdout = api.json.output(revision_data['cl_info'])
       yield api.step_data(step_name, stdout=stdout)