Cleans up style problems in architecture.py and test_runner.py

tools/utils.py

 # Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 # This file contains a set of utilities functions used by other Python-based
 # scripts.
 
 import commands
 import os
 import platform
@@ skipping 179 matching lines @@
   if os.fork() > 0:
     return False
   os.setsid()
   if os.fork() > 0:
     os._exit(0)
     raise
   return True
 
 
 def PrintError(str):
+  """Writes and flushes a string to stderr."""
   sys.stderr.write(str)
   sys.stderr.write('\n')
 
 
+def CheckedUnlink(name):
+  """Unlink a file without throwing an exception."""
+  try:
+    os.unlink(name)
+  except OSError, e:
+    PrintError("os.unlink() " + str(e))
+
+
 def Main(argv):
   print "GuessOS() -> ", GuessOS()
   print "GuessArchitecture() -> ", GuessArchitecture()
   print "GuessCpus() -> ", GuessCpus()
   print "IsWindows() -> ", IsWindows()
 
 
 class Error(Exception):
   pass
 
 
 class ToolError(Exception):
   """Deprecated exception, use Error instead."""
 
   def __init__(self, value):
     self.value = value
 
   def __str__(self):
     return repr(self.value)
 
 
 if __name__ == "__main__":
   import sys
   Main(sys.argv)