Add an interactive ui test for double clicking on web content.

Refine existing MouseLeaveTest for more general mouse event testing.
(renames, add click handlers, add basic test, cleanup helpers and html)

Add a test that triggers click/double click handlers in html content.

Remove IsX11SendEventTrue filtering to allow ui_controls double clicks.
Originally added in https://chromiumcodereview.appspot.com/11761027
(I think to prevent reposted clicks from counting as double clicks)
(crrev.com/c/980662's GetRepeatCount timestamp checks should suffice)

TODO: try to enable more disabled tests, update cited bugs.

Bug: 825695
Test: Automated; no double click when dismissing menus, no regressions.
Change-Id: Iefcc2d313b36710a18e5c94079aa5dd75d8500bf
Reviewed-on: https://chromium-review.googlesource.com/985904
Commit-Queue: Michael Wasserman <[email protected]>
Reviewed-by: Scott Violet <[email protected]>
Cr-Commit-Position: refs/heads/master@{#547347}
7 files changed