droger, mattcary: can you help triage?

I'll take a look.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/d254b1a069254f7cfec69a9be9a2331374f5d7a0

commit d254b1a069254f7cfec69a9be9a2331374f5d7a0
Author: Giovanni Ortuño Urquidi <ortuno@chromium.org>
Date: Thu Jun 15 06:31:45 2017

sheriff: disable flaky NoStatePrefetchBrowserTest.AppCacheRegistered on mac

https://luci-milo.appspot.com/buildbot/chromium.mac/Mac10.11%20Tests/13910

TBR=mattcary@chromium.org, droger@chromium.org

Bug:  733504 
Change-Id: Ic87963cc35a3124bb5b303d5949aee609f594f5a
Reviewed-on: https://chromium-review.googlesource.com/536577
Commit-Queue: Giovanni Ortuño Urquidi <ortuno@chromium.org>
Reviewed-by: Matthew Cary <mattcary@chromium.org>
Reviewed-by: Giovanni Ortuño Urquidi <ortuno@chromium.org>
Cr-Commit-Position: refs/heads/master@{#479624}
[modify] https://crrev.com/d254b1a069254f7cfec69a9be9a2331374f5d7a0/chrome/browser/prerender/prerender_nostate_prefetch_browsertest.cc

Thanks!

Notes:

Failed in NoStatePrefetchBrowserTest:WaitForAppCache, which may be a sign that there was some problem with the appcache initialization in the tests.

It flakes very irregularly, but it seems to happen on all platforms (for linux and windows, it seems to have passed after a run or two). So this is probably not mac-specific.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/3b32efaba81015f0f4aae00726bbcdeb0623bb9c

commit 3b32efaba81015f0f4aae00726bbcdeb0623bb9c
Author: mattcary <mattcary@chromium.org>
Date: Mon Jul 03 10:22:20 2017

Prerender: Add timeout to appcache waiting in NoStatePrefetch browser test.

This may fix flakiness in this test. I have not been able to reproduce the
flakes locally, so I'll have to observe the dashboard and see if this eliminates
the occasional timeout.

BUG= 733504 

Review-Url: https://codereview.chromium.org/2968723002
Cr-Commit-Position: refs/heads/master@{#483979}

[modify] https://crrev.com/3b32efaba81015f0f4aae00726bbcdeb0623bb9c/chrome/browser/prerender/prerender_nostate_prefetch_browsertest.cc

Will monitor on linux to see if this fixes the occasional timeouts; if so it probably fixes the mac issue and I'll re-enable the test on that platform.

No more timeouts on linux, but still occasional timeouts on windows. So the fix was part of the solution but not the complete one. I will continue to dig...

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/21c8ba3dd60b3ba6c5245bfae90a5d2cf1168325

commit 21c8ba3dd60b3ba6c5245bfae90a5d2cf1168325
Author: Matthew Cary <mattcary@chromium.org>
Date: Fri Sep 15 13:02:01 2017

Prerender: tweak NoStatePrefetch AppCache test to avoid timeouts.

Rearranging wait for AppCache. This doesn't change the semantics of the
test. See bug for history.

BUG:  733504 
Bug: 
Change-Id: I1d013cf6840f86763f9cf4866743cbb7566964fd
Reviewed-on: https://chromium-review.googlesource.com/668373
Reviewed-by: Alexandr Ilin <alexilin@chromium.org>
Commit-Queue: Matthew Cary <mattcary@chromium.org>
Cr-Commit-Position: refs/heads/master@{#502235}
[modify] https://crrev.com/21c8ba3dd60b3ba6c5245bfae90a5d2cf1168325/chrome/browser/prerender/prerender_nostate_prefetch_browsertest.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/5b7386ebf7fa7da0819e9049c97db8651ac9d73d

commit 5b7386ebf7fa7da0819e9049c97db8651ac9d73d
Author: Matthew Cary <mattcary@chromium.org>
Date: Tue Sep 26 09:26:11 2017

Prerender: re-enable NoStatePrefetchBrowserTest.AppCacheRegistered.

crrev.com/c/668373 seems to have eliminated the flakiness of
NoStatePrefetchBrowserTest.AppCacheRegistered on linux and windows
platforms. This CL renables the test on Mac as well.

Bug:  733504 
Change-Id: I0bae4b3eea4220dc70e8189b4c3b20bde1d4e754
Reviewed-on: https://chromium-review.googlesource.com/684334
Reviewed-by: Alexandr Ilin <alexilin@chromium.org>
Commit-Queue: Matthew Cary <mattcary@chromium.org>
Cr-Commit-Position: refs/heads/master@{#504324}
[modify] https://crrev.com/5b7386ebf7fa7da0819e9049c97db8651ac9d73d/chrome/browser/prerender/prerender_nostate_prefetch_browsertest.cc

No flakes in the last day, with any luck querying for the appcache state after each navigation has eliminated the hidden race.