Do not actually remove trees when test bisect in dry-run mode

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 38 matching lines @@
 
 sys.path.append(os.path.join(
     os.path.dirname(__file__), os.path.pardir, 'telemetry'))
 
 import bisect_utils
 import builder
 import math_utils
 import request_build
 import source_control as source_control_module
 import ttest
-from telemetry.util import cloud_storage
+from telemetry.util import cloud_storage # pylint: disable=F0401

[Sergiy Byelozyorov, 2014/09/19 12:35:59]

This was necessary for PRESUBMIT to pass

[ojan, 2014/09/19 17:42:52]

I don't think this is the best fix for this. It looks like
telemetry/telemetry/util is what this is importing. So the other script that
runs this file must have telemetry on it's python path or be run from the
telemetry directory. Ideally we'd fix all the things to do imports from the
root, but that's a big change. So, instead, I think you should change pylint to
put the root telemetry directory in sys.path.

I *think* you need to modify
https://code.google.com/p/chromium/codesearch#chromium/src/PRESUBMIT.py to make
that happen. I don't know for sure though. maruel, do you know this stuff?

[M-A Ruel, 2014/09/20 00:47:44]

pylint is not run from src/PRESUBMIT.py because there's no project level
consistent sys.path setup. It's the one in tools/auto_bisect. There's a way to
pass additional paths to the check.

[Sergiy Byelozyorov, 2014/09/22 20:04:15]

Done.

 
 # Below is the map of "depot" names to information about each depot. Each depot
 # is a repository, and in the process of bisecting, revision ranges in these
 # repositories may also be bisected.
 #
 # Each depot information dictionary may contain:
 #   src: Path to the working directory.
 #   recurse: True if this repository will get bisected.
 #   depends: A list of other repositories that are actually part of the same
 #       repository in svn. If the repository has any dependent repositories
@@ skipping 3338 matching lines @@
       # 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())