hasn't flaked in a ~week, removing sheriff label. Related to issue 461856?

__main__.InstallerTest.MigrateMultiStrandedBinariesOnInstall is flaky.

Findit has detected 3 new flake occurrences of this test. List
of all flake occurrences can be found at:
https://findit-for-me.appspot.com/flake/occurrences?key=ag9zfmZpbmRpdC1mb3ItbWVyZQsSBUZsYWtlIlpjaHJvbWl1bUBtaW5pX2luc3RhbGxlcl90ZXN0c0BfX21haW5fXy5JbnN0YWxsZXJUZXN0Lk1pZ3JhdGVNdWx0aVN0cmFuZGVkQmluYXJpZXNPbkluc3RhbGwM.

Since this test is still flaky, this issue has been moved back onto the Sheriff
Bug Queue if it's not already there.

If the result above is wrong, please file a bug using this link:
https://bugs.chromium.org/p/chromium/issues/entry?status=Unconfirmed&labels=Pri-1,Test-Findit-Wrong&components=Tools%3ETest%3EFindit%3EFlakiness&summary=%5BFindit%5D%20Flake%20Detection%20-%20Wrong%20result%20for%20__main__.InstallerTest.MigrateMultiStrandedBinariesOnInstall&comment=Link%20to%20flake%20occurrences%3A%20https://findit-for-me.appspot.com/flake/occurrences?key=ag9zfmZpbmRpdC1mb3ItbWVyZQsSBUZsYWtlIlpjaHJvbWl1bUBtaW5pX2luc3RhbGxlcl90ZXN0c0BfX21haW5fXy5JbnN0YWxsZXJUZXN0Lk1pZ3JhdGVNdWx0aVN0cmFuZGVkQmluYXJpZXNPbkluc3RhbGwM

Automatically posted by the findit-for-me app (https://goo.gl/Ot9f7N).

 Issue 899920  has been merged into this issue.

 Issue 899895  has been merged into this issue.

 Issue 899888  has been merged into this issue.

Unexpected Failures:
* __main__.InstallerTest.ChromeUserLevel
* __main__.InstallerTest.ChromeUserLevelUpdate
* __main__.InstallerTest.MigrateMultiNoBinaries
* __main__.InstallerTest.MigrateMultiSimple
* __main__.InstallerTest.MigrateMultiStrandedBinariesOnInstall
* __main__.InstallerTest.MigrateMultiStrandedBinariesOnUpdate

cc johnchen@ because error is also related to test_chrome_with_chromedriver.py.
Traceback (most recent call last):
  File "test_chrome_with_chromedriver.py", line 132, in <module>
    sys.exit(main())
  File "test_chrome_with_chromedriver.py", line 121, in main
    with CreateChromedriver(args) as driver:
  File "C:\b\s\w\ir\.swarming_module\bin\Lib\contextlib.py", line 17, in __enter__
    return self.gen.next()
  File "test_chrome_with_chromedriver.py", line 72, in CreateChromedriver
    chrome_options=chrome_options)
  File "C:\b\s\w\ir\chrome\test\mini_installer\..\..\..\third_party\webdriver\pylib\selenium\webdriver\chrome\webdriver.py", line 66, in __init__
    desired_capabilities=desired_capabilities)
  File "C:\b\s\w\ir\chrome\test\mini_installer\..\..\..\third_party\webdriver\pylib\selenium\webdriver\remote\webdriver.py", line 64, in __init__
    self.start_session(desired_capabilities, browser_profile)
  File "C:\b\s\w\ir\chrome\test\mini_installer\..\..\..\third_party\webdriver\pylib\selenium\webdriver\remote\webdriver.py", line 106, in start_session
    'desiredCapabilities': desired_capabilities,
  File "C:\b\s\w\ir\chrome\test\mini_installer\..\..\..\third_party\webdriver\pylib\selenium\webdriver\remote\webdriver.py", line 157, in execute
    self.error_handler.check_response(response)
  File "C:\b\s\w\ir\chrome\test\mini_installer\..\..\..\third_party\webdriver\pylib\selenium\webdriver\remote\errorhandler.py", line 149, in check_response
    raise exception_class(message, screen, stacktrace)
selenium.common.exceptions.WebDriverException: Message: u"unknown error: Chrome failed to start: crashed\n  (unknown error: DevToolsActivePort file doesn't exist)\n  (The process started from chrome location C:\\Users\\chrome-bot\\AppData\\Local\\Chromium\\Application\\chrome.exe is no longer running, so ChromeDriver is assuming that Chrome has crashed.)\n  (Driver info: chromedriver=2.43.603804 (e38c957b43accd61aece5fa59c46f2e5fa316961),platform=Windows NT 10.0.15063 x86_64)" 
ERROR

I'm building locally to see if I can repro. Generally, this sort of failure has nothing to do specifically with the mini installer tests, but is rather a problem with chrome.exe launching and talking to chromedriver.

I am seeing occasional DCHECKs being hit in chrome.exe when run by the test. I suspect this is what's happening. Here's one example:

[7464:6848:1030/154408.188:FATAL:field_trial.cc(842)] Check failed: result.

I'm not sure what's happening on the bot, though, as this sort of failing should be visible in the test output.

 Issue 900384  has been merged into this issue.

Is there any progress on this?
There is  issue 901267  about all __main__.InstallerTest tests flaking due to the same reason.

 Issue 901267  has been merged into this issue.

I think some of these failures are a result of r603171. The timing looks about right. I'm working on reverting that now. If this is correct, I expect that the failures happen each day after the update to chrome/VERSION and then settle down after bots reboot. We'll see what happens.

The revert landed at r605299. Let's see if the flakiness persists after that.

I'm fairly sure that was it. Looking at failures on Win 7 Tests x64 (1), for example, there's a cluster of failed runs each time chrome-release-bot bumps the BUILD number in chrome/VERSION.

I'm calling this fixed for now.