[Sharded Perf Tests] Disambiguate same benchmark on different steps

[Sharded Perf Tests] Disambiguate same benchmark on different steps

Override the benchmark_name of a telemetry test if it is being run
on a step (test_name) with a different name.

BUG=541542
Committed: https://crrev.com/a4e76ad9ea2066e88eb04eb6290c2c883358c4a5
Cr-Commit-Position: refs/heads/master@{#354298}

[perezju, 2015-10-15 14:15:45]

perezju@chromium.org changed reviewers:
+ eakuefner@chromium.org, jbudorick@chromium.org

[jbudorick, 2015-10-15 14:19:17]

lgtm

[perezju, 2015-10-15 14:54:16]

Ethan, let me know if this sounds reasonable to you, so I can go ahead and land
it.

[eakuefner, 2015-10-15 15:48:22]

On 2015/10/15 at 14:54:16, perezju wrote:
> Ethan, let me know if this sounds reasonable to you, so I can go ahead and
land it.

lgtm

Given the number of downstream tests affected by this, it seems okay to do this,
especially since those seem like tests that we don't eventually intend to
migrate upstream. The upstream perf waterfall enforces that the Telemetry
benchmark name is the same as the test name by using Telemetry to list perf
tests, which is appropriate for the standard use case.

I wish it were possible to do this sort of thing without having to introspect on
chart JSON, but because the amount of rewriting is minimal here, I think it's
acceptable. We were also talking about extending this to also take into account
the dashboard-side milestone tagging that the downstream waterfall had before
the switch to chart JSON.

[perezju, 2015-10-15 16:13:55]

The CQ bit was checked by perezju@chromium.org

[commit-bot: I haz the power, 2015-10-15 16:14:18]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1403263002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1403263002/1

[commit-bot: I haz the power, 2015-10-15 17:48:13]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-10-15 17:49:18]

Patchset 1 (id:??) landed as
https://crrev.com/a4e76ad9ea2066e88eb04eb6290c2c883358c4a5
Cr-Commit-Position: refs/heads/master@{#354298}