Yields the valus in each section.

def RawData(self):
    """Yields the valus in each section."""
    result = collections.OrderedDict()

    i = 0
    while True:
      try:
        name, value, value_type = winreg.EnumValue(self._AccessRootKey(), i)
        # Only support strings here.
        if value_type == winreg.REG_SZ:
          precondition.AssertType(value, Text)
          result[name] = value
      except OSError:
        break

      i += 1

    return result