Avoid bisecting revision prior to r265549 on android bots

tools/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 2955 matching lines @@
 
       cmd = ['log', '--format=%ct', '-1', bad_revision]
       output = CheckRunGit(cmd, cwd=cwd)
       bad_commit_time = int(output)
 
       return good_commit_time <= bad_commit_time
     else:
       # Cros/svn use integers
       return int(good_revision) <= int(bad_revision)
 
+  def CanPerformBisect(self, revision_to_check):
+    """Checks whether a given revision is bisectable.
+
+    Note: At present it checks whether a given revision is bisectable on
+    android bots(refer crbug.com/385324).
+
+    Args:
+      revision_to_check: Known good revision.
+
+    Returns:
+      A dictionary indicating the result. If revision is not bisectable,
+      this will contain the field "error", otherwise None.
+    """
+    if self.opts.target_platform == 'android':
+      revision_to_check = self.source_control.SVNFindRev(revision_to_check)
+      if IsStringInt(revision_to_check) and revision_to_check < 265549:
+        return {'error': (
+            'Bisect cannot conitnue for the given revision range.\n'
+            'It is impossible to bisect Android regressions '
+            'prior to r265549, which allows the bisect bot to '
+            'rely on Telemetry to do apk installation of the most recently '
+            'built local ChromeShell(refer to crbug.com/385324).\n'
+            'Please try bisecting revisions greater than or equal to r265549.')}
+    return None
+
   def Run(self, command_to_run, bad_revision_in, good_revision_in, metric):
     """Given known good and bad revisions, run a binary search on all
     intermediate revisions to determine the CL where the performance regression
     occurred.
 
     Args:
         command_to_run: Specify the command to execute the performance test.
         good_revision: Number/tag of the known good revision.
         bad_revision: Number/tag of the known bad revision.
         metric: The performance metric to monitor.
@@ skipping 66 matching lines @@
       results['error'] = 'bad_revision < good_revision, did you swap these '\
           'by mistake?'
       return results
 
     (bad_revision, good_revision) = self.NudgeRevisionsIfDEPSChange(
         bad_revision, good_revision)
 
     if self.opts.output_buildbot_annotations:
       bisect_utils.OutputAnnotationStepStart('Gathering Revisions')
 
+    cannot_bisect = self.CanPerformBisect(good_revision)
+    if cannot_bisect:
+      results['error'] = cannot_bisect.get('error')
+      return results
+
     print 'Gathering revision range for bisection.'
     # Retrieve a list of revisions to do bisection on.
     src_revision_list = self.GetRevisionList(target_depot,
                                              bad_revision,
                                              good_revision)
 
     if self.opts.output_buildbot_annotations:
       bisect_utils.OutputAnnotationStepClosed()
 
     if src_revision_list:
@@ skipping 1074 matching lines @@
       # The perf dashboard scrapes the "results" step in order to comment on
       # bugs. If you change this, please update the perf dashboard as well.
       bisect_utils.OutputAnnotationStepStart('Results')
     print 'Error: %s' % e.message
     if opts.output_buildbot_annotations:
       bisect_utils.OutputAnnotationStepClosed()
   return 1
 
 if __name__ == '__main__':
   sys.exit(main())