Removes a pathspec from the list of pathspecs.

def _RemoveCompletedPathspec(self, index):
    """Removes a pathspec from the list of pathspecs."""
    pathspec = self.state.indexed_pathspecs[index]
    request_data = self.state.request_data_list[index]

    self.state.indexed_pathspecs[index] = None
    self.state.request_data_list[index] = None
    self.state.pending_hashes.pop(index, None)
    self.state.pending_files.pop(index, None)

    # We have a bit more room in the pending_hashes so we try to schedule
    # another pathspec.
    self._TryToStartNextPathspec()
    return pathspec, request_data