The code in ui_controls send events directly to the platform-window [1]. So the event from there should follow the usual targeting codepath in aura and then in content.

/cc+ wjmaclean@ and kenrb@ for webview expertise.

[1] https://cs.chromium.org/chromium/src/ui/base/test/ui_controls_internal_win.cc?type=cs&g=0&l=520

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/e844955e99742cacbdc5cf320863e081498869d2

commit e844955e99742cacbdc5cf320863e081498869d2
Author: Ria Jiang <riajiang@chromium.org>
Date: Fri May 25 14:26:10 2018

Disable WebViewInteractiveTest.KeyboardFocusSimple on Win.

WebViewInteractiveTest.KeyboardFocusSimple flakily times out on some
Windows test bots.

Bug: 846695
Change-Id: Ia15a0244b2857d1b58d74c6f3dd86cc621f02105
Reviewed-on: https://chromium-review.googlesource.com/1073111
Reviewed-by: James MacLean <wjmaclean@chromium.org>
Commit-Queue: Ria Jiang <riajiang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#561863}
[modify] https://crrev.com/e844955e99742cacbdc5cf320863e081498869d2/chrome/browser/apps/guest_view/web_view_interactive_browsertest.cc

This bug has an owner, thus, it's been triaged. Changing status to "assigned".

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/ec52747a5abc25a862843edca761104b3c319764

commit ec52747a5abc25a862843edca761104b3c319764
Author: Gabriel Charette <gab@chromium.org>
Date: Mon Jan 14 16:16:49 2019

[ui_controls] Unflake Send*NotifyWhenDone() on Windows

ui_controls::Send*NotifyWhenDone() can be flaky when invoked after
ui_controls::Send*() as the former can decide to notify based on
observing a yet-to-be-processed event from the latter (or even a
yet-to-be-processed event emitted by unrelated code) and thus notify too
early, resuming and testing conditions that have yet to be met.

Solution: defer the notification if the system queue has pending events
of the same type awaiting dispatch.

Note: mouse move can be repeated indefinitely during a drag, as such we
consider a mouse move complete when it hits the target regardless of
remaining mouse move messages in the queue.

@ BUG OWNERS : This might unflake many currently disabled tests. I've
CC'ed interactive_ui_tests + Windows bugs, please try to re-enable your
test after this CL if you think it might be related.

Bug:  892228 , 640996, 897801,893078,876224,875443,873110,852786,850343,848049,846695,840369,798492,756338,751031,665296,651906,499858,468660,419468,238347,131612,106489,97777,92467
Change-Id: I548856a3948ff71a145435799b4ba3e689561f14
Reviewed-on: https://chromium-review.googlesource.com/c/1392178
Reviewed-by: Sadrul Chowdhury <sadrul@chromium.org>
Reviewed-by: Greg Thompson <grt@chromium.org>
Reviewed-by: Peter Kasting <pkasting@chromium.org>
Commit-Queue: Gabriel Charette <gab@chromium.org>
Cr-Commit-Position: refs/heads/master@{#622470}
[modify] https://crrev.com/ec52747a5abc25a862843edca761104b3c319764/chrome/browser/ui/views/bookmarks/bookmark_bar_view_test.cc
[modify] https://crrev.com/ec52747a5abc25a862843edca761104b3c319764/ui/base/test/ui_controls_internal_win.cc