Make bisect tool check for new V8 roll description, "based on <git-hash>"

tools/auto_bisect/bisect_perf_regression.py

 #!/usr/bin/env python
 # Copyright (c) 2013 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.
 
 """Performance Test Bisect Tool
 
 This script bisects a series of changelists using binary search. It starts at
 a bad revision where a performance metric has regressed, and asks for a last
 known-good revision. It will then binary search across this revision range by
@@ skipping 1864 matching lines @@
       # "Version 3.X.Y (based on bleeding_edge revision rZ)"
       # So we can just try parsing that out first and fall back to the old way.
       v8_dir = self.depot_registry.GetDepotDir('v8')
       v8_bleeding_edge_dir = self.depot_registry.GetDepotDir('v8_bleeding_edge')
 
       revision_info = source_control.QueryRevisionInfo(revision, cwd=v8_dir)
       version_re = re.compile("Version (?P<values>[0-9,.]+)")
       regex_results = version_re.search(revision_info['subject'])
       if regex_results:
         git_revision = None
-        # TODO (prasadv): Support the v8 git migration based subject
-        # "based on <githash>"
-        # Look for "based on bleeding_edge" and parse out revision
         if 'based on bleeding_edge' in revision_info['subject']:
           try:
             bleeding_edge_revision = revision_info['subject'].split(
                 'bleeding_edge revision r')[1]
             bleeding_edge_revision = int(bleeding_edge_revision.split(')')[0])
             bleeding_edge_url = ('https://v8.googlecode.com/svn/branches/'
                                  'bleeding_edge@%s' % bleeding_edge_revision)
             cmd = ['log',
                    '--format=%H',
                    '--grep',
                    bleeding_edge_url,
                    '-1',
                    bleeding_edge_branch]
             output = bisect_utils.CheckRunGit(cmd, cwd=v8_dir)
             if output:
               git_revision = output.strip()
             return git_revision
           except (IndexError, ValueError):
             pass
+        else:
+          # V8 rolls description changed after V8 git migration, new description
+          # includes "Version 3.X.Y (based on <git hash>)"
+          try:
+            rxp = re.compile('based on (?P<git_revision>[a-fA-F0-9]+)')
+            re_results = rxp.search(revision_info['subject'])
+            if re_results:
+              return re_results.group('git_revision')
+          except (IndexError, ValueError):
+            pass
         if not git_revision:
           # Wasn't successful, try the old way of looking for "Prepare push to"
           git_revision = source_control.ResolveToRevision(
               int(commit_position) - 1, 'v8_bleeding_edge',
               bisect_utils.DEPOT_DEPS_NAME, -1, cwd=v8_bleeding_edge_dir)
 
           if git_revision:
             revision_info = source_control.QueryRevisionInfo(git_revision,
                 cwd=v8_bleeding_edge_dir)
 
@@ skipping 1020 matching lines @@
       bisect_utils.OutputAnnotationStepStart('Results')
     print 'Error: ', e.message
     logging.warn('A RuntimeError was caught: %s', e.message)
     if opts.output_buildbot_annotations:
       bisect_utils.OutputAnnotationStepClosed()
   return 1
 
 
 if __name__ == '__main__':
   sys.exit(main())