Hi Martin,

Please take a look this flaky test.

 Issue 829340  has been merged into this issue.

Also

PolicyToolUITest.RenameSessionInvalidName
PolicyToolUITest.RenameSessionWithExistingSessionName

Flaky tests are P1, please address.

Flake:

../../chrome/browser/ui/webui/policy_tool_ui_browsertest.cc(259): error: Value of: value
  Actual: false
Expected: true
Received fatal exception EXCEPTION_ACCESS_VIOLATION
Backtrace:
	PolicyToolUITest::ExtractSinglePolicyValue [0x006C6FC0+238]
	PolicyToolUITest_RenameSessionWithExistingSessionName_Test::RunTestOnMainThread [0x006CA1A8+120]
	content::BrowserTestBase::ProxyRunTestOnMainThreadLoop [0x02AB677E+446]
	ChromeBrowserMainParts::PreMainMessageLoopRunImpl [0x031747C8+3300]
	ChromeBrowserMainParts::PreMainMessageLoopRun [0x03173A26+166]
	content::BrowserMainLoop::PreMainMessageLoopRun [0x0172D144+68]
	content::StartupTaskRunner::RunAllTasksNow [0x01A5172A+30]
	content::BrowserMainLoop::CreateStartupTasks [0x0172C1E7+783]
	content::BrowserMainRunnerImpl::Initialize [0x0172F414+100]
	content::BrowserMain [0x0172A4EA+138]
	content::RunNamedProcessTypeMain [0x028F752C+148]
	content::ContentMainRunnerImpl::Run [0x028F7A67+279]
	service_manager::Main [0x03D44C59+677]
	content::ContentMain [0x028F743F+51]
	content::BrowserTestBase::SetUp [0x02AB64F0+1872]
	InProcessBrowserTest::SetUp [0x02A24AAF+447]
	testing::Test::Run [0x00D3A33D+105]
	testing::TestInfo::Run [0x00D3AAC1+203]
	testing::TestCase::Run [0x00D3AEE5+237]
	testing::internal::UnitTestImpl::RunAllTests [0x00D41025+629]
	testing::UnitTest::Run [0x00D40CAB+153]
	base::TestSuite::Run [0x02A3C858+100]
	ChromeTestSuiteRunner::RunTestSuite [0x05C4449C+44]
	content::LaunchTests [0x02AB72BD+413]
	LaunchChromeTests [0x05C44839+257]
	main [0x05C44433+111]
	__scrt_common_main_seh [0x0671E27A+248] (f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:283)
	BaseThreadInitThunk [0x769A338A+18]
	RtlInitializeExceptionChain [0x77579F72+99]
	RtlInitializeExceptionChain [0x77579F45+54]

Might be related to issue 797446 (there already are disabled PolicyToolUITests because of that bug)

Taking a stab with https://chromium-review.googlesource.com/#/c/chromium/src/+/1005918 but I will own this issue beyond that. Thanks!

Nvm, ui_test_utils::NavigateToURL is already blocking so this wasn't it.

Back to you.

Insight from bauerb :

"""
Not directly. (BTW, https://crbug.com/797446 basically has no actionable information, because there is only a link to the flakiness dashboard, where all logs have already expired). Anyway, some thoughts:

The tests don't have very good logging in case of failures. For example, if the policy in ExtractSinglePolicyValue() can't be found, you could print the whole dictionary. Similarly, comparing two base::Values doesn't result in a very good error message when it fails -- really, you could stringify the values and compare those.
NavigateToURL() will wait for the page load to finish, but the Javascript on the page might not be fully ready yet. I don't know much about how the policy tool UI is implemented, but in the JS file there is an event listener that calls an initialization method (https://cs.chromium.org/chromium/src/chrome/browser/resources/policy_tool.js?l=322&rcl=d573c76d2c89bff6763e0648a33383091d0b9174) -- you might want to wait for that to happen.
"""

PolicyToolUITest.CreatingSessionFiles flaked in https://ci.chromium.org/buildbot/chromium.chromiumos/linux-chromeos-rel/7073

This is quite flaky.

https://test-results.appspot.com/dashboards/flakiness_dashboard.html#tests=PolicyToolUITest.DefaultSession shows this is happening quite often. 

 Issue 834492  has been merged into this issue.

See also bug 832673 and bug 835846.

CL to disable test: https://chromium-review.googlesource.com/1025315

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/e4d3f0773712da4de8bb67ed5b46ea41edf10217

commit e4d3f0773712da4de8bb67ed5b46ea41edf10217
Author: Lei Zhang <thestig@chromium.org>
Date: Fri Apr 27 19:30:56 2018

Disable flaky PolicyToolUITest.DefaultSession

BUG=826700

Change-Id: I7cd5a32bb227d5ad07f8d0941aff922e10793790
Reviewed-on: https://chromium-review.googlesource.com/1025315
Reviewed-by: Georges Khalil <georgesak@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
Cr-Commit-Position: refs/heads/master@{#554451}
[modify] https://crrev.com/e4d3f0773712da4de8bb67ed5b46ea41edf10217/chrome/browser/ui/webui/policy_tool_ui_browsertest.cc