Stuff changed around these for Issue 674904 (r542064)

failures are all linux currently, errors like

[30718:30914:0308/223729.101689:ERROR:bus.cc(394)] Failed to connect to the bus: Could not parse server address: Unknown address type (examples of valid types are "tcp" and on UNIX "unix")
[1:1:0308/223729.177209:ERROR:runtime_enabled_features.cc(1442)] RuntimeEnabledFeature not recognized: VibrateRequiresUserGesture
(browser_tests:30718): LIBDBUSMENU-GLIB-WARNING **: Unable to get session bus: Unknown or unsupported transport 'disabled' for address 'disabled:'
LaunchProcess: failed to execvp:
xdg-desktop-menu
[1:1:0308/223729.314916:ERROR:runtime_enabled_features.cc(1442)] RuntimeEnabledFeature not recognized: VibrateRequiresUserGesture
LaunchProcess: failed to execvp:
xdg-icon-resource
[30718:30900:0308/223729.373717:WARNING:shell_integration_linux.cc(324)] Could not install icon chrome-bjeodlgnchgjbiglapdooknacnngcflb-Default.png at size 512.
LaunchProcess: failed to execvp:
xdg-desktop-menu
[1:1:0308/223729.735451:ERROR:runtime_enabled_features.cc(1442)] RuntimeEnabledFeature not recognized: VibrateRequiresUserGesture
[30718:30718:0308/223730.358301:INFO:CONSOLE(283)] "<webview>: The load has aborted with error -3: ERR_ABORTED.", source: extensions::webViewEvents (283)
../../chrome/browser/apps/guest_view/web_view_browsertest.cc:679: Failure
Value of: done_listener.WaitUntilSatisfied()
  Actual: false
Expected: true
[30718:30892:0308/223730.448898:WARNING:discardable_shared_memory_manager.cc(436)] Some MojoDiscardableSharedMemoryManagerImpls are still alive. They will be leaked.
[30718:30718:0308/223730.451813:WARNING:url_request_context_getter.cc(43)] URLRequestContextGetter leaking due to no owning thread.
[  FAILED  ] WebViewTests/WebViewTest.Shim_TestNestedSubframes/1, where GetParam() = true (2190 ms)

It is ironic to make a test flakier with a CL named "Fix flaky <webview> tests"
My CL is the causes of this, but I don't think it should be reverted. The tests need to be disabled until the cause of the flake is found.

My CL causes "webview.onloadstop" event handler to be called only once instead of repeatedly. I suspect there is a source of flakiness elsewhere and calling it repeatedly caused the test to be retried several time until it succeed.

I will disabled the test and try to find a solution.

I read #1 to quickly.
I just figured out that the 5 recent flakes happened **before** my patch. So it is not the cause of this. There is even a chance it has fixed the issue.

Let me know if this test fails one more time from now on.

Nothing yet. Taking out of alerts.

I am not seeing any new failures in:
https://test-results.appspot.com/dashboards/flakiness_dashboard.html#tests=WebViewTests%2FWebViewTest.Shim_TestNestedSubframes%2F1
and nothing new in:
https://chromium-try-flakes.appspot.com/all_flake_occurrences?key=ahVzfmNocm9taXVtLXRyeS1mbGFrZXNyPgsSBUZsYWtlIjNXZWJWaWV3VGVzdHMvV2ViVmlld1Rlc3QuU2hpbV9UZXN0TmVzdGVkU3ViZnJhbWVzLzEM

I am closing the bug. I suppose my CL fixed it.