Somewhat related,
  RootConsumesScrollDuringOverscrollGesture/1 and 2
fails with unexpected render widget host.

[ RUN      ] SitePerProcessHitTestBrowserTest.RootConsumesScrollDuringOverscrollGesture/1
[221722:221789:0914/101032.740413:ERROR:network_service.cc(84)] Not implemented reached in std::unique_ptr<net::NetworkChangeNotifier> network::(anonymous namespace)::CreateNetworkChangeNotifierIfNeeded()
[221722:221722:0914/101032.789162:ERROR:gpu_interface_provider.cc(85)] Not implemented reached in virtual void content::GpuInterfaceProvider::RegisterOzoneGpuInterfaces(service_manager::BinderRegistry *)

DevTools listening on ws://127.0.0.1:41309/devtools/browser/9762b7d8-c5fe-4876-824d-e5c7b917930e
[221722:221722:0914/101032.796249:ERROR:proxy_resolution_service.cc(1556)] ProxyConfigService for ChromeOS should be created in profile_io_data.cc::CreateProxyConfigService and this should be used only for examples.
[221722:221722:0914/101032.853361:ERROR:render_widget_host_view_aura.cc(1255)] Not implemented reached in virtual base::i18n::TextDirection content::RenderWidgetHostViewAura::GetTextDirection() const
[221722:221722:0914/101033.367484:ERROR:layer_tree_host_impl.cc(3060)] Forcing zero-copy tile initialization as worker context is missing
[1:8:0914/101033.394637:ERROR:layer_tree_host_impl.cc(3060)] Forcing zero-copy tile initialization as worker context is missing
[1:8:0914/101033.640396:ERROR:layer_tree_host_impl.cc(3060)] Forcing zero-copy tile initialization as worker context is missing
../../content/browser/site_per_process_hit_test_browsertest.cc:1676: Failure
Expected equality of these values:
  rwhv_child->GetRenderWidgetHost()
    Which is: 0x142b75bd020
  router->GetRenderWidgetHostAtPoint(rwhv_root, point_in_child, &dont_care)
    Which is: 0x142b71f1020
Stack trace:
#0 0x0000015a4bc0 StackTraceGetter::CurrentStackTrace()
#1 0x0000015c9a97 testing::internal::UnitTestImpl::CurrentOsStackTraceExceptTop()
#2 0x0000015c8efd testing::internal::AssertHelper::operator=()
#3 0x000000fac857 content::SitePerProcessHitTestBrowserTest_RootConsumesScrollDuringOverscrollGesture_Test::RunTestOnMainThread()
#4 0x0000024d205e content::BrowserTestBase::ProxyRunTestOnMainThreadLoop()

SitePerProcessHitTestDataGenerationBrowserTest.ClipPathOOPIF/1
SitePerProcessHitTestDataGenerationBrowserTest.ClipPathOOPIF/2

After crrev.com/c/1233174, the frame sink/aura::Window mismatch problem is gone. Now the test fails with different errors.

e.g.

SitePerProcessHitTestBrowserTest.HitTestNestedFrames/1 now fails with

../../content/browser/site_per_process_hit_test_browsertest.cc:4873: Failure
The difference between returned_point.x() and 5 is 52, which exceeds 2, where
returned_point.x() evaluates to 57,
5 evaluates to 5, and
2 evaluates to 2.
Stack trace:
#0 0x0000015c8770 StackTraceGetter::CurrentStackTrace()
#1 0x0000015ed647 testing::internal::UnitTestImpl::CurrentOsStackTraceExceptTop()
#2 0x0000015ecaad testing::internal::AssertHelper::operator=()
#3 0x000000fef13a content::SitePerProcessHitTestBrowserTest_HitTestNestedFrames_Test::RunTestOnMainThread()

Might be related to issue 879308

Dup into  issue 884360  since the hit test failure cause is the same.