Make submit_try accept space- or comma-separated list

tools/submit_try

 #!/usr/bin/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.
 
 
 """
 submit_try: Submit a try request.
 
@@ skipping 160 matching lines @@
     elif arg == '-l' or arg == '--list_bots':
       print 'submit_try: Available builders:\n  %s' % '\n  '.join(trybots)
       sys.exit(0)
     elif arg == '-b' or arg == '--bot':
       if using_bots:
         Error('--bot specified multiple times.')
       if len(argv) < 1:
         Error('You must specify a builder with "--bot".')
       using_bots = []
       while argv and not argv[0].startswith('-'):
-        bot = argv.pop(0)
-        if bot == ALL_BUILDERS:
-          if using_bots:
-            Error('Cannot specify "all" with additional builder names.')
-          using_bots = trybots
-          break
-        else:
-          if not bot in trybots:
-            Error('Unrecognized builder: %s' % bot)
-          using_bots.append(bot)
+        for bot in argv.pop(0).split(','):
+          if bot == ALL_BUILDERS:
+            if using_bots:
+              Error('Cannot specify "all" with additional builder names.')
+            using_bots = trybots
+            break
+          else:
+            if not bot in trybots:
+              Error('Unrecognized builder: %s' % bot)
+            using_bots.append(bot)
     elif arg == '-r':
       if len(argv) < 1:
         Error('You must specify a revision with "-r".')
       revision = argv.pop(0)
     else:
       if changelist or not is_svn:
         Error('Unknown argument: %s' % arg)
       changelist = arg
   if is_svn and not changelist:
     Error('You must specify a changelist name.')
@@ skipping 53 matching lines @@
   is_svn = os.path.isdir('.svn')
 
   # Parse and validate the command-line arguments.
   args = ValidateArgs(sys.argv[1:], trybots=trybots, is_svn=is_svn)
 
   # Submit the try request.
   SubmitTryRequest(args, is_svn=is_svn)
 
 
 if __name__ == '__main__':
-  sys.exit(main())
+  sys.exit(main())