Fix run_tests to always run from the crashpad directory

build/run_tests.py

 #!/usr/bin/env python
 
 # Copyright 2014 The Crashpad Authors. All rights reserved.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
 #
 #     http://www.apache.org/licenses/LICENSE-2.0
 #
 # Unless required by applicable law or agreed to in writing, software
 # distributed under the License is distributed on an "AS IS" BASIS,
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
 import os
 import subprocess
 import sys
 
-script_dir = os.path.dirname(__file__)
-crashpad_dir = os.path.dirname(script_dir) if script_dir is not '' else '..'
-
 
 # This script is primarily used from the waterfall so that the list of tests
 # that are run is maintained in-tree, rather than in a separate infrastructure
 # location in the recipe.
 def main(args):
   if len(args) != 1:
     print >>sys.stderr, 'usage: run_tests.py {Debug|Release}'
     return 1;
-  binary_dir = os.path.join(crashpad_dir, 'out', args[0])
+
+  # Until https://code.google.com/p/crashpad/issues/detail?id=4 is fixed, tests
+  # need to be run from a specific working directory.
+  crashpad_dir = \
+      os.path.join(os.path.dirname(os.path.abspath(__file__)), os.pardir)
+  os.chdir(crashpad_dir)
+
+  binary_dir = os.path.join('out', args[0])
   tests = [
       'client_test',
       'minidump_test',
       'snapshot_test',
       'util_test',
   ]
   for test in tests:
     print '-' * 80
     print test
     print '-' * 80
     subprocess.check_call(os.path.join(binary_dir, test))
   return 0
 
 
 if __name__ == '__main__':
   sys.exit(main(sys.argv[1:]))