This test sometimes flakes in this manner:

[ RUN      ] ExtensionFetchTest.ExtensionCanFetchHostedResourceWithHostPermissions
Xlib:  extension "RANDR" missing on display ":99".
[1213:1213:0407/055130.585126:WARNING:audio_manager.cc(295)] Multiple instances of AudioManager detected
[1213:1213:0407/055130.585145:WARNING:audio_manager.cc(254)] Multiple instances of AudioManager detected
[1213:1213:0407/055130.650523:WARNING:password_store_factory.cc(249)] Using basic (unencrypted) store for password storage. See https://chromium.googlesource.com/chromium/src/+/master/docs/linux_password_storage.md for more information about password storage options.
BrowserTestBase received signal: Terminated. Backtrace:
#0 0x000002903e97 base::debug::StackTrace::StackTrace()
#1 0x000002e6b376 content::(anonymous namespace)::DumpStackTraceSignalHandler()
#2 0x7fca38488cb0 <unknown>
#3 0x7fca3854284d __poll
#4 0x7fca3dfb5fe4 <unknown>
#5 0x7fca3dfb60ec g_main_context_iteration
#6 0x00000291d906 base::MessagePumpGlib::Run()
#7 0x00000291bb27 base::MessageLoop::RunHandler()
#8 0x00000293a54e base::RunLoop::Run()
#9 0x000002e92541 content::MessageLoopRunner::Run()
#10 0x0000029a0962 content::DOMMessageQueue::WaitForMessage()
#11 0x00000299f765 content::(anonymous namespace)::ExecuteScriptHelper()
#12 0x00000299f64e content::ExecuteScriptAndExtractString()
#13 0x0000012bfad3 extensions::browsertest_util::ExecuteScriptInBackgroundPage()
#14 0x0000012c4d38 ExtensionBrowserTest::ExecuteScriptInBackgroundPage()
#15 0x000000af48ec extensions::(anonymous namespace)::ExtensionFetchTest_ExtensionCanFetchHostedResourceWithHostPermissions_Test::RunTestOnMainThread()
#16 0x0000029aedcf InProcessBrowserTest::RunTestOnMainThreadLoop()
#17 0x000002e6b0d8 content::BrowserTestBase::ProxyRunTestOnMainThreadLoop()
#18 0x000002cdb9f4 ChromeBrowserMainParts::PreMainMessageLoopRunImpl()
#19 0x000002cdaa9b ChromeBrowserMainParts::PreMainMessageLoopRun()
#20 0x000001971eaf content::BrowserMainLoop::PreMainMessageLoopRun()
#21 0x000001c37ed7 content::StartupTaskRunner::RunAllTasksNow()
#22 0x000001970165 content::BrowserMainLoop::CreateStartupTasks()
#23 0x000001974764 content::BrowserMainRunnerImpl::Initialize()
#24 0x00000196d8c2 content::BrowserMain()
#25 0x0000028ee27c content::ContentMainRunnerImpl::Run()
#26 0x000003ebe59f service_manager::Main()
#27 0x0000028ed2f2 content::ContentMain()
#28 0x000002e6aa19 content::BrowserTestBase::SetUp()
#29 0x0000029ad4c0 InProcessBrowserTest::SetUp()
#30 0x00000347127e testing::Test::Run()
#31 0x000003471df0 testing::TestInfo::Run()
#32 0x000003472317 testing::TestCase::Run()
#33 0x000003479357 testing::internal::UnitTestImpl::RunAllTests()
#34 0x000003478fd7 testing::UnitTest::Run()
#35 0x0000029be6b1 base::TestSuite::Run()
#36 0x0000028f8a78 ChromeTestSuiteRunner::RunTestSuite()
#37 0x000002e8ebea content::LaunchTests()
#38 0x0000028f89f7 main
#39 0x7fca38473f45 __libc_start_main
#40 0x0000005fe80d <unknown>

The test dashboard shows that it fails this way every so often: https://test-results.appspot.com/dashboards/flakiness_dashboard.html#tests=ExtensionFetchTest.ExtensionCanFetchHostedResourceWithHostPermissions&testType=site_per_process_browser_tests

rdevlin.cronin@, can you take a look please? :)