Previous good build:
https://ci.chromium.org/buildbot/chromium.fyi/Site%20Isolation%20Android/15340

Comparing this good shard:
https://chromium-swarm.appspot.com/task?id=3a5b25fa55eb6010&refresh=10&show_raw=1

to this bad one:
https://chromium-swarm.appspot.com/task?id=3a5b7074c2a80010&refresh=10&show_raw=1

I realize I changed the command line argument --gtest-filter-file to --test-launcher-filter-file . Thought these were identical; guess not? Putting it back the way it was.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/fceb9a030c182e939a436a540e6dacc70f161cb1

commit fceb9a030c182e939a436a540e6dacc70f161cb1
Author: Kenneth Russell <kbr@chromium.org>
Date: Thu Dec 14 03:13:32 2017

Use --gtest-filter-file on Site Isolation Android bot.

This was an inadvertent change not documented in
http://crrev.com/523031 and broke the test suite on this bot.

Since it's difficult to remove the --test-launcher-filter-file
argument which is currently being ignored, leave that as is for the
moment.

BUG= 794749 
NOTRY=true

Change-Id: Ib0bd2cb9cbfe3f7d72281369bdd1e991e1b591f6
Reviewed-on: https://chromium-review.googlesource.com/826464
Commit-Queue: Kenneth Russell <kbr@chromium.org>
Reviewed-by: John Budorick <jbudorick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#523995}
[modify] https://crrev.com/fceb9a030c182e939a436a540e6dacc70f161cb1/testing/buildbot/chromium.fyi.json
[modify] https://crrev.com/fceb9a030c182e939a436a540e6dacc70f161cb1/testing/buildbot/test_suite_exceptions.pyl

The change above landed in this build:
https://ci.chromium.org/buildbot/chromium.fyi/Site%20Isolation%20Android/15471

site_per_process_content_browsertests passed in that build. Unfortunately, site_per_process_components_unittests failed, timing out apparently because of oversubscription of Swarming capacity.

In the next build:
https://ci.chromium.org/buildbot/chromium.fyi/Site%20Isolation%20Android/15472

site_per_process_content_browsertests failed but because SitePerProcessBrowserTest.CrossProcessInertSubframe flaked:

[ RUN      ] SitePerProcessBrowserTest.CrossProcessInertSubframe
[WARNING:dns_config_service_posix.cc(341)] Failed to read DnsConfig.
[ERROR:devtools_http_handler.cc(249)] Cannot start http server for devtools. Stop devtools.
[ERROR:shell_android.cc(72)] Not implemented reached in void content::Shell::PlatformSetTitle(const base::string16 &): Cross-site iframe factory
[WARNING:render_frame_host_impl.cc(2716)] OnDidStopLoading was called twice.
[WARNING:render_frame_host_impl.cc(2716)] OnDidStopLoading was called twice.
referenceTable head length=54 1
../../content/browser/site_per_process_browsertest.cc:11575: Failure
Expected equality of these values:
  ""
  focused_element
    Which is: "text1"
[  FAILED  ] SitePerProcessBrowserTest.CrossProcessInertSubframe, where TypeParam =  and GetParam() =  (1367 ms)


This test isn't marked in src/testing/buildbot/filters/site-per-process.content_browsertests.filter so it has to be some other unrelated issue. Indeed, it flaked at least on https://ci.chromium.org/buildbot/chromium.fyi/Site%20Isolation%20Android/15316 , before my original change.

nasko@, others, I'm closing this as verified because the problem I introduced is definitely fixed. However, if I seem to have broken something else, please reopen or file a new bug. Thanks.