Never mind! For battor.steady_state, we're just gonna use the same names to avoid a need for migration (the benchmark is getting reworked in the relatively near future anyways)

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/419395f5fe84ee90f49ac0e9099d979e29994c93

commit 419395f5fe84ee90f49ac0e9099d979e29994c93
Author: ashleymarie <ashleymarie@chromium.org>
Date: Fri Jun 02 15:35:04 2017

Explicitly settings story names for the battor.steady_state story set.

BUG= chromium:720002 
BUG= chromium:728003 

Review-Url: https://codereview.chromium.org/2910673002
Cr-Commit-Position: refs/heads/master@{#476668}

[modify] https://crrev.com/419395f5fe84ee90f49ac0e9099d979e29994c93/tools/perf/page_sets/idle_after_loading_stories.py