Configure the logging subsystem.

def LogInit():
  """Configure the logging subsystem."""
  logging.debug("Initializing client logging subsystem.")

  # The root logger.
  logger = logging.getLogger()
  memory_handlers = [
      m for m in logger.handlers
      if m.__class__.__name__ == "PreLoggingMemoryHandler"
  ]

  # Clear all handers.
  logger.handlers = list(GetLogHandlers())
  SetLogLevels()

  # Now flush the old messages into the log files.
  for handler in memory_handlers:
    for record in handler.buffer:
      logger.handle(record)