SingleClientPrintersSyncTest.EditPrinter is flaky. Original CL at [1].

An example failure is at [2]. Here is failing test output:

  SingleClientPrintersSyncTest.EditPrinter (run #1):
  [ RUN      ] SingleClientPrintersSyncTest.EditPrinter
  [17562:17562:0315/144654.094677:WARNING:chrome_browser_main_chromeos.cc(369)] Running as stub user with profile dir: test-user
  [17562:17562:0315/144654.291175:WARNING:audio_manager.cc(295)] Multiple instances of AudioManager detected
  [17562:17562:0315/144654.291199:WARNING:audio_manager.cc(254)] Multiple instances of AudioManager detected
  [17562:17562:0315/144654.384443:WARNING:signin_screen_policy_provider.cc(61)] Denying load of Extension  : ahfgeienlihckogmohjhadlkjgocpleb / Web Store because of 'signin_screen' is only allowed for packaged apps, but this is a hosted app.
  [17562:17562:0315/144654.384492:WARNING:signin_screen_policy_provider.cc(61)] Denying load of Extension  : eemcgdkfndhakfknompkggombfjjjeno / Bookmark Manager because of 'signin_screen' is only allowed for packaged apps, but this is a extension.
  [17562:17562:0315/144654.384522:WARNING:signin_screen_policy_provider.cc(61)] Denying load of Extension  : mgndgikekgjfcpckkfioiadnlibdjbkf / Chromium because of 'signin_screen' is only allowed for packaged apps, but this is a hosted app.
  [17562:17562:0315/144654.384543:WARNING:signin_screen_policy_provider.cc(61)] Denying load of Extension  : nkoccljplnhpfnfiajclkommnmllphnl / crosh_builtin because of 'signin_screen' is only allowed for packaged apps, but this is a extension.
  [17562:17608:0315/144654.389860:WARNING:freezer_cgroup_process_manager.cc(61)] Cgroup freezer does not exist or is not writable. Unable to freeze renderer processes.
  [17562:17562:0315/144654.510661:WARNING:signin_screen_policy_provider.cc(61)] Denying load of Extension  : ahfgeienlihckogmohjhadlkjgocpleb / Web Store because of 'signin_screen' is only allowed for packaged apps, but this is a hosted app.
  [17562:17562:0315/144654.510711:WARNING:signin_screen_policy_provider.cc(61)] Denying load of Extension  : eemcgdkfndhakfknompkggombfjjjeno / Bookmark Manager because of 'signin_screen' is only allowed for packaged apps, but this is a extension.
  [17562:17562:0315/144654.510748:WARNING:signin_screen_policy_provider.cc(61)] Denying load of Extension  : mgndgikekgjfcpckkfioiadnlibdjbkf / Chromium because of 'signin_screen' is only allowed for packaged apps, but this is a hosted app.
  [17562:17562:0315/144654.510791:WARNING:signin_screen_policy_provider.cc(61)] Denying load of Extension  : nkoccljplnhpfnfiajclkommnmllphnl / crosh_builtin because of 'signin_screen' is only allowed for packaged apps, but this is a extension.
  [17562:17777:0315/144654.959036:WARNING:syncer_proto_util.cc(338)] Error posting from syncer: Response Code (bogus on error): -1 Content-Length (bogus on error): -1 Server Status: SYNC_AUTH_ERROR
  [17562:17777:0315/144654.959814:WARNING:sync_encryption_handler_impl.cc(971)] Nigori had empty encryption keybag.
  [17562:17777:0315/144654.960184:WARNING:sync_encryption_handler_impl.cc(971)] Nigori had empty encryption keybag.
  [17562:17562:0315/144654.966081:ERROR:chrome_signin_client.cc(179)] Device ID is not set for user.
  [17562:17777:0315/144654.968188:WARNING:sync_encryption_handler_impl.cc(347)] Ignoring new implicit passphrase. Keystore migration already performed.
  [17562:17562:0315/144655.314252:FATAL:printers_sync_bridge.cc(89)] Check failed: store_.
  #0 0x000001e0dbc7 base::debug::StackTrace::StackTrace()
  #1 0x000001e205ca logging::LogMessage::~LogMessage()
  #2 0x0000019d397b chromeos::PrintersSyncBridge::AddPrinter()
  #3 0x0000019d1f2b chromeos::PrintersManager::RegisterPrinter()
  #4 0x000001cb1bc9 printers_helper::AddPrinter()
  #5 0x000000459f86 SingleClientPrintersSyncTest_EditPrinter_Test::RunTestOnMainThread()
  #6 0x000001ccc407 InProcessBrowserTest::RunTestOnMainThreadLoop()
  #7 0x000005394913 content::BrowserTestBase::ProxyRunTestOnMainThreadLoop()
  #8 0x0000020956c6 ChromeBrowserMainParts::PreMainMessageLoopRunImpl()
  #9 0x0000020947f1 ChromeBrowserMainParts::PreMainMessageLoopRun()
  #10 0x00000184097f chromeos::ChromeBrowserMainPartsChromeos::PreMainMessageLoopRun()
  #11 0x0000009da695 content::BrowserMainLoop::PreMainMessageLoopRun()
  #12 0x000000ca8636 content::StartupTaskRunner::RunAllTasksNow()
  #13 0x0000009d884b content::BrowserMainLoop::CreateStartupTasks()
  #14 0x0000009dd7cc content::BrowserMainRunnerImpl::Initialize()
  #15 0x0000009d6038 content::BrowserMain()
  #16 0x000001c6dcec content::ContentMainRunnerImpl::Run()
  #17 0x000001c6c8d0 content::ContentMain()
  #18 0x00000539425a content::BrowserTestBase::SetUp()
  #19 0x000001ccb89e InProcessBrowserTest::SetUp()
  #20 0x000001cc06d8 SyncTest::SetUp()
  #21 0x000001d4e70e testing::Test::Run()
  #22 0x000001d4eff0 testing::TestInfo::Run()
  #23 0x000001d4f367 testing::TestCase::Run()
  #24 0x000001d563c7 testing::internal::UnitTestImpl::RunAllTests()
  #25 0x000001d56047 testing::UnitTest::Run()
  #26 0x000001df96d1 base::TestSuite::Run()
  #27 0x000001ccae4b ChromeTestSuiteRunner::RunTestSuite()
  #28 0x000005395b87 content::LaunchTests()
  #29 0x000001c9a0a1 main
  #30 0x7fadf3805f45 __libc_start_main
  #31 0x00000043a161 <unknown>
    
1: https://chromium.googlesource.com/chromium/src/+/5be8b586be828f6c54d153f74a5af39c96645377
2: https://build.chromium.org/p/chromium.chromiumos/builders/Linux%20ChromiumOS%20Ozone%20Tests%20%281%29/builds/44114