def _LoadPathmap(pathmap_path):
  """Load the pathmap of obfuscated resource paths.

  Returns: A dict mapping from obfuscated paths to original paths or an
           empty dict if passed a None |pathmap_path|.
  """
  if pathmap_path is None:
    return {}

  pathmap = {}
  with open(pathmap_path, 'r') as f:
    for line in f:
      line = line.strip()
      if line.startswith('--') or line == '':
        continue
      original, renamed = line.split(' -> ')
      pathmap[renamed] = original
  return pathmap