fix dom.py -- initdir was not right if running from a relative path

tools/dom/dom.py

 #!/usr/bin/python
 
 # Copyright (c) 2013, 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.
 
 # A script which makes it easy to execute common DOM-related tasks
 
 import os
 import subprocess
 import sys
 from sys import argv
 
 sys.path.append(os.path.join(os.path.dirname(__file__), '..'))
 import utils
 
 dart_out_dir = utils.GetBuildRoot(utils.GuessOS(), 'release', 'ia32')
 if utils.IsWindows():
   dart_bin = os.path.join(dart_out_dir, 'dart.exe')
 else:
   dart_bin = os.path.join(dart_out_dir, 'dart')
 
+dart_dir = os.path.abspath(os.path.join(
+    os.path.dirname(os.path.realpath(__file__)),
+    os.path.pardir, os.path.pardir))
+
 def help():
   print('Helper script to make it easy to perform common tasks encountered '
      'during the life of a Dart DOM developer.\n'
      '\n'
      'For example, to re-generate DOM classes then run a specific test:\n'
      '  dom.py gen test_drt html/element_test\n'
      '\n'
      'Or re-generate DOM classes and run the Dart analyzer:\n'
      '  dom.py gen analyze\n')
   print('Commands: ')
@@ skipping 126 matching lines @@
 def call(args):
   print ' '.join(args)
   pipe = subprocess.Popen(args, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
   output, error = pipe.communicate()
   if output:
     print output
   if error:
     print error
   return pipe.returncode
 
-def init_dir():
-  ''' Makes sure that we're always rooted in the dart root folder.'''
-  dart_dir = os.path.abspath(os.path.join(
-      os.path.dirname(os.path.realpath(__file__)),
-      os.path.pardir, os.path.pardir))
-  os.chdir(dart_dir)
-
 commands = {
   'analyze': [analyze, 'Run the dart analyzer'],
   'build': [build, 'Build dart in release mode'],
   'dart2js': [dart2js, 'Run dart2js on the .dart file specified'],
   'dartc': [dartc, 'Runs dartc in release mode'],
   'docs': [docs, 'Generates docs.json'],
   'gen': [gen, 'Re-generate DOM generated files (run go.sh)'],
   'size_check': [size_check, 'Check the size of dart2js compiled Swarm'],
   'test_docs': [test_docs, 'Tests docs.dart'],
   'test_chrome': [test_chrome, 'Run tests in checked mode in Chrome.\n'
       '\t\tOptionally provide name of test to run.'],
   'test_drt': [test_drt, 'Run tests in checked mode in DumpRenderTree.\n'
       '\t\tOptionally provide name of test to run.'],
   'test_ff': [test_ff, 'Run tests in checked mode in Firefox.\n'
       '\t\tOptionally provide name of test to run.'],
   'http_server': [http_server, 'Starts the testing server for manually '
       'running browser tests.'],
 }
 
 def main():
   success = True
   argv.pop(0)
 
   if not argv:
     help()
     success = False
 
   while (argv):
-    init_dir()
+    # Make sure that we're always rooted in the dart root folder.
+    os.chdir(dart_dir)
     command = argv.pop(0)
 
     if not command in commands:
       help();
       success = False
       break
     returncode = commands[command][0]()
     success = success and not bool(returncode)
 
   sys.exit(not success)
 
 if __name__ == '__main__':
   main()