[Swarming] Presort tests - slowest first.

[Swarming] Presort tests - slowest first.

Swarming won't support an incremental data file. By just
sorting the lowest hanging fruits to the beginning we
already get a big bang for the buck (>80% of the improvement
we get otherwise).

This will require semi-regular manual updates of the
slowest tests.

BUG=chromium:535160
LOG=n

Committed: https://crrev.com/366dc81143d2b2d4f58a4974ae528f081b05690b
Cr-Commit-Position: refs/heads/master@{#31061}

[Michael Achenbach, 2015-10-01 14:56:54]

The CQ bit was checked by machenbach@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-10-01 14:57:11]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1385443002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1385443002/1

[Michael Achenbach, 2015-10-01 14:59:25]

machenbach@chromium.org changed reviewers:
+ jkummerow@chromium.org, tandrii@chromium.org

[Michael Achenbach, 2015-10-01 14:59:35]

PTAL

[commit-bot: I haz the power, 2015-10-01 15:00:03]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-10-01 15:00:04]

Dry run: Try jobs failed on following builders:
  v8_mac_rel on tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_mac_rel/builds/10282)

[Michael Achenbach, 2015-10-01 15:02:21]

The CQ bit was checked by machenbach@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-10-01 15:02:38]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1385443002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1385443002/20001

[tandrii(chromium), 2015-10-01 15:11:28]

lgtm in spirit, but I have no idea about .status files.

[commit-bot: I haz the power, 2015-10-01 16:08:18]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-10-01 16:08:19]

Dry run: This issue passed the CQ dry run.

[Jakob Kummerow, 2015-10-01 16:16:27]

Hm... the perf data collection mechanism would solve this problem without the
need for manual maintenance, but I guess bots clobber the perf data file after
every run, right? Any chance we can fix that?

If we can't, then this CL is fine as an alternative.

[tandrii(chromium), 2015-10-01 16:56:30]

On 2015/10/01 16:16:27, Jakob wrote:
> Hm... the perf data collection mechanism would solve this problem without the
> need for manual maintenance, but I guess bots clobber the perf data file after
> every run, right? Any chance we can fix that?
> 
> If we can't, then this CL is fine as an alternative.

The bot on which this runs isn't fixed, it's one from a big pool of bots, so if
if there was some local cache, you'd be better off not relying on it.

[Michael Achenbach, 2015-10-01 19:16:33]

On 2015/10/01 16:56:30, tandrii(chromium) wrote:
> On 2015/10/01 16:16:27, Jakob wrote:
> > Hm... the perf data collection mechanism would solve this problem without
the
> > need for manual maintenance, but I guess bots clobber the perf data file
after
> > every run, right? Any chance we can fix that?
> > 
> > If we can't, then this CL is fine as an alternative.
> 
> The bot on which this runs isn't fixed, it's one from a big pool of bots, so
if
> if there was some local cache, you'd be better off not relying on it.

Maybe we find something between these two solutions at some point. Right now, on
the bots we're not winning so much more after manually  marking 2-3 of the
slowest tests in each suite. And with swarming in general we'll hopefully win
more than we loose by loosing this feature...

[Michael Achenbach, 2015-10-01 19:16:52]

The CQ bit was checked by machenbach@chromium.org

[commit-bot: I haz the power, 2015-10-01 19:17:05]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1385443002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1385443002/20001

[commit-bot: I haz the power, 2015-10-01 19:19:12]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-10-01 19:19:24]

Patchset 2 (id:??) landed as
https://crrev.com/366dc81143d2b2d4f58a4974ae528f081b05690b
Cr-Commit-Position: refs/heads/master@{#31061}