The test was added in https://codereview.chromium.org/2852763002

Here is the earliest reported failure:

[ RUN      ] AXSystemCaretWinTest.TestMovingWindow
e:\b\c\b\win\src\ui\views\accessibility\ax_system_caret_win_interactive_uitest.cc(148): error: Expected: (AccessibleObjectFromWindow( hwnd, static_cast<DWORD>(((LONG)0xFFFFFFF8)), IID_IAccessible, reinterpret_cast<void**>(caret_accessible.GetAddressOf()))) succeeds.
  Actual: 0x80004005 Unspecified error
[3948:4144:0629/192410.327:23787235:FATAL:scoped_comptr.h(130)] Check failed: ptr_.
Backtrace:
	base::debug::StackTrace::StackTrace [0x00000001421AC615+69]
	base::debug::StackTrace::StackTrace [0x00000001421BC8E3+19]
	logging::LogMessage::~LogMessage [0x00000001420F8D0B+91]
	base::win::ScopedComPtr<`anonymous namespace'::ITrayNotifyWin8>::operator-> [0x000000014272ECE6+86]
	views::AXSystemCaretWinTest_TestMovingWindow_Test::TestBody [0x000000014026956B+379]
	testing::internal::HandleExceptionsInMethodIfSupported<testing::TestCase,void> [0x000000014027CC0D+61]
	testing::Test::Run [0x000000014028787A+122]
	testing::TestInfo::Run [0x0000000140287A71+161]
	testing::TestCase::Run [0x0000000140287955+165]
	testing::internal::UnitTestImpl::RunAllTests [0x0000000140287E22+562]
	testing::internal::HandleExceptionsInMethodIfSupported<testing::internal::UnitTestImpl,bool> [0x000000014027CCAD+61]
	testing::UnitTest::Run [0x0000000140287BB9+217]
	base::TestSuite::Run [0x00000001420EA179+137]
	InteractiveUITestSuiteRunner::RunTestSuite [0x00000001401D3978+72]
	content::LaunchTests [0x00000001419DD1C6+710]
	LaunchChromeTests [0x000000014194CB0E+94]
	main [0x00000001401D3A60+96]
	__scrt_common_main_seh [0x000000014492B909+285] (f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:253)
	BaseThreadInitThunk [0x00000000772B59CD+13]
	RtlUserThreadStart [0x00000000773EA561+33]

The most recent failure looks the same.

Revert is in CQ: https://codereview.chromium.org/2965933002/

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/82160e95b43bb9c65a8ff6d6a52f3b6dffd48b32

commit 82160e95b43bb9c65a8ff6d6a52f3b6dffd48b32
Author: foolip <foolip@chromium.org>
Date: Mon Jul 03 09:53:01 2017

Revert of Added a system caret used for accessibility on Windows. (patchset #30 id:580001 of https://codereview.chromium.org/2852763002/ )

Reason for revert:
AXSystemCaretWinTest.TestMovingWindow is flaky.

BUG=738617

Original issue's description:
> Added a system caret used for accessibility on Windows.
>
> Screen magnifiers need to know where the caret is located so that they can show a magnified caret allowing the user to more easily track it.
> Existing screen magnifiers, such as the built-in Windows Magnifier, require a system caret to be present in order to track it. However, Chrome doesn't use the system caret.
> This is an object that implements the same accessibility interface that would have been returned by the system if the system caret had been used.
> R=dmazzoni@chromium.org, shuchen@chromium.org, ellyjones@chromium.org, ananta@chromium.org, sky@chromium.org, sadrul@chromium.org
>
> Review-Url: https://codereview.chromium.org/2852763002
> Cr-Original-Commit-Position: refs/heads/master@{#483558}
> Committed: https://chromium.googlesource.com/chromium/src/+/3fc0df1e01ab7e17318ce50724890f939bc00fa4
> Review-Url: https://codereview.chromium.org/2852763002
> Cr-Commit-Position: refs/heads/master@{#483825}
> Committed: https://chromium.googlesource.com/chromium/src/+/99936ad737f80a465b479d6bc0abacd22767deaf

TBR=ananta@chromium.org,dmazzoni@chromium.org,ellyjones@chromium.org,sadrul@chromium.org,shuchen@chromium.org,sky@chromium.org,nektar@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.

Review-Url: https://codereview.chromium.org/2965933002
Cr-Commit-Position: refs/heads/master@{#483973}

[modify] https://crrev.com/82160e95b43bb9c65a8ff6d6a52f3b6dffd48b32/chrome/test/BUILD.gn
[modify] https://crrev.com/82160e95b43bb9c65a8ff6d6a52f3b6dffd48b32/content/browser/renderer_host/legacy_render_widget_host_win.cc
[modify] https://crrev.com/82160e95b43bb9c65a8ff6d6a52f3b6dffd48b32/content/browser/renderer_host/legacy_render_widget_host_win.h
[modify] https://crrev.com/82160e95b43bb9c65a8ff6d6a52f3b6dffd48b32/ui/accessibility/BUILD.gn
[rename] https://crrev.com/82160e95b43bb9c65a8ff6d6a52f3b6dffd48b32/ui/accessibility/platform/ax_fake_caret_win.cc
[rename] https://crrev.com/82160e95b43bb9c65a8ff6d6a52f3b6dffd48b32/ui/accessibility/platform/ax_fake_caret_win.h
[modify] https://crrev.com/82160e95b43bb9c65a8ff6d6a52f3b6dffd48b32/ui/base/ime/input_method_observer.h
[modify] https://crrev.com/82160e95b43bb9c65a8ff6d6a52f3b6dffd48b32/ui/base/ime/input_method_win.cc
[modify] https://crrev.com/82160e95b43bb9c65a8ff6d6a52f3b6dffd48b32/ui/views/accessibility/DEPS
[delete] https://crrev.com/cca92b36ff221cd329cde25a2ee26e8c8a077c70/ui/views/accessibility/ax_system_caret_win_interactive_uitest.cc
[modify] https://crrev.com/82160e95b43bb9c65a8ff6d6a52f3b6dffd48b32/ui/views/controls/textfield/textfield.cc
[modify] https://crrev.com/82160e95b43bb9c65a8ff6d6a52f3b6dffd48b32/ui/views/widget/desktop_aura/desktop_window_tree_host_win.cc
[modify] https://crrev.com/82160e95b43bb9c65a8ff6d6a52f3b6dffd48b32/ui/views/widget/desktop_aura/desktop_window_tree_host_win.h
[modify] https://crrev.com/82160e95b43bb9c65a8ff6d6a52f3b6dffd48b32/ui/views/win/hwnd_message_handler.cc
[modify] https://crrev.com/82160e95b43bb9c65a8ff6d6a52f3b6dffd48b32/ui/views/win/hwnd_message_handler.h
[modify] https://crrev.com/82160e95b43bb9c65a8ff6d6a52f3b6dffd48b32/ui/views/win/hwnd_message_handler_delegate.h

Re-landed the affected patch with the flaky test disabled. I am assigning this bug to myself to further investigate and fix the flaky test.

A few common causes of flakes in interactive_ui_tests have just been fixed. Please re-evaluate these disabled tests. They may no longer be flaky. Thanks.

Caret tracking.

Not planning to work on this during Q4.