Apply user per-summary size guidance overrides.

def tensor_size_guidance_from_flags(flags):
  """Apply user per-summary size guidance overrides."""

  tensor_size_guidance = dict(DEFAULT_TENSOR_SIZE_GUIDANCE)
  if not flags or not flags.samples_per_plugin:
    return tensor_size_guidance

  for token in flags.samples_per_plugin.split(','):
    k, v = token.strip().split('=')
    tensor_size_guidance[k] = int(v)

  return tensor_size_guidance