Set appropriate working directory on build failure

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 1507 matching lines @@
     return (None, None)
 
   def BuildCurrentRevision(self, depot, revision=None):
     """Builds chrome and performance_ui_tests on the current revision.
 
     Returns:
       True if the build was successful.
     """
     if self.opts.debug_ignore_build:
       return True
+
+    build_success = False
     cwd = os.getcwd()

[qyearsley, 2014/09/09 00:59:57]

(Note, somewhat unrelated to this CL: this variable name could probably be
improved. cwd stands for "current working directory", and once you chdir away
from it, it's no longer the current working directory... same goes for
"src_cwd". Should probably just be called "src_dir".)

     os.chdir(self.src_cwd)
     # Fetch build archive for the given revision from the cloud storage when
     # the storage bucket is passed.
     if self.IsDownloadable(depot) and revision:
       deps_patch = None
       if depot != 'chromium':
         # Create a DEPS patch with new revision for dependency repository.
         revision, deps_patch = self.CreateDEPSPatch(depot, revision)
       if self.DownloadCurrentBuild(revision, patch=deps_patch):
-        os.chdir(cwd)
         if deps_patch:
           # Reverts the changes to DEPS file.
           self.source_control.CheckoutFileAtRevision(
               bisect_utils.FILE_DEPS, revision, cwd=self.src_cwd)
-        return True
-      return False
-
-    # These codes are executed when bisect bots builds binaries locally.
-    build_success = self.builder.Build(depot, self.opts)
+        build_success = True
+    else:
+      # These codes are executed when bisect bots builds binaries locally.
+      build_success = self.builder.Build(depot, self.opts)
     os.chdir(cwd)
     return build_success
 
   def RunGClientHooks(self):
     """Runs gclient with runhooks command.
 
     Returns:
       True if gclient reports no errors.
     """
     if self.opts.debug_ignore_build:
@@ skipping 1839 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())