Change logging statements to not use the "%" operator.

third_party/WebKit/Tools/Scripts/webkitpy/common/system/executive.py

 # Copyright (c) 2009, Google Inc. All rights reserved.
 # Copyright (c) 2009 Apple Inc. All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 # notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
@@ skipping 130 matching lines @@
         # to work in cygwin, however it occasionally raises EAGAIN.
         retries_left = 10 if sys.platform == "cygwin" else 1
         while retries_left > 0:
             try:
                 retries_left -= 1
                 os.kill(pid, signal.SIGKILL)
                 _ = os.waitpid(pid, os.WNOHANG)
             except OSError as e:
                 if e.errno == errno.EAGAIN:
                     if retries_left <= 0:
-                        _log.warn("Failed to kill pid %s.  Too many EAGAIN errors." % pid)
+                        _log.warning("Failed to kill pid %s.  Too many EAGAIN errors.", pid)
                     continue
                 if e.errno == errno.ESRCH:  # The process does not exist.
                     return
                 if e.errno == errno.EPIPE:  # The process has exited already on cygwin
                     return
                 if e.errno == errno.ECHILD:
                     # Can't wait on a non-child process, but the kill worked.
                     return
                 if e.errno == errno.EACCES and sys.platform == 'cygwin':
                     # Cygwin python sometimes can't kill native processes.
@@ skipping 208 matching lines @@
 
         # run_command automatically decodes to unicode() unless explicitly told not to.
         if decode_output:
             output = output.decode(self._child_process_encoding(), errors="replace")
 
         # wait() is not threadsafe and can throw OSError due to:
         # http://bugs.python.org/issue1731717
         exit_code = process.wait()
 
         if debug_logging:
-            _log.debug('"%s" took %.2fs' % (self.command_for_printing(args), time.time() - start_time))
+            _log.debug('"%s" took %.2fs', self.command_for_printing(args), time.time() - start_time)
 
         if return_exit_code:
             return exit_code
 
         if exit_code:
             script_error = ScriptError(script_args=args,
                                        exit_code=exit_code,
                                        output=output,
                                        cwd=cwd)
             (error_handler or self.default_error_handler)(script_error)
@@ skipping 66 matching lines @@
             pool.close()
             pool.join()
 
 
 def _run_command_thunk(cmd_line_and_cwd):
     # Note that this needs to be a bare module (and hence Picklable) method to work with multiprocessing.Pool.
     (cmd_line, cwd) = cmd_line_and_cwd
     proc = subprocess.Popen(cmd_line, cwd=cwd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
     stdout, stderr = proc.communicate()
     return (proc.returncode, stdout, stderr)