Remove pathspec for this index and call the FileFetchFailed method.

def _FileFetchFailed(self, index, request_name):
    """Remove pathspec for this index and call the FileFetchFailed method."""

    pathspec, request_data = self._RemoveCompletedPathspec(index)

    # Report the request_data for this flow's caller.
    self.FileFetchFailed(pathspec, request_name, request_data=request_data)