Resolve flakiness in VideoControlsManager tests and re-enable them

[heycam]

f83459d

Resolve flakiness in VideoControlsManager tests and re-enable them
https://bugs.webkit.org/show_bug.cgi?id=175909
rdar://problem/42793000

Reviewed by Eric Carlson.

The primary issue with the flakiness of these tests is that they run
some script, e.g. "muteFirstVideoAndScrollToSecondVideo()", and then
immediately add a handler for a message that the page sends in response
to running that script. Depending on timing, the Web process can end up
sending the message before the UI process has added the handler.

This patch adds a new expectControlsManager function that takes a setup
function to run after the message handler is added but before we start
waiting for the message.

A secondary issue affects
VideoControlsManagerMultipleVideosSwitchControlledVideoWhenScrolling:
the setTimeout callback in the test file that sends the "scrolled"
message after performing the scroll to the second video uses a timeout
of 0ms. Since bug 221124, setTimeout(..., 0) callbacks get run first the
next time around the event loop, and this means the UI process does not
get a chance to be informed about the change in active
PlaybackSessionContextIdentifier (through a SetUpPlaybackControlsManagerWithID
message) before it continues to the request the controlled element ID.
That request is made using the old PlaybackSessionContextIdentifier. To
resolve this, we bump the timeout to 1ms (the effective minimum before
bug 221124) so that the SetUpPlaybackControlsManagerWithID message is
sent first.

* Tools/TestWebKitAPI/Tests/WebKitCocoa/VideoControlsManager.mm:
(-[VideoControlsManagerTestWebView expectControlsManager:afterReceivingMessage:]):
(-[VideoControlsManagerTestWebView expectControlsManager:afterReceivingMessage:withSetup:]):
(TestWebKitAPI::TEST):
* Tools/TestWebKitAPI/Tests/WebKitCocoa/large-videos-autoplaying-scroll-to-video.html:

Canonical link: https://commits.webkit.org/255057@main

c2113f2

Misc	iOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 🧪 win
✅ 🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-debug	✅ 🛠 gtk	✅ 🛠 wincairo
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	✅ 🛠 mac-AS-debug	✅ 🧪 gtk-wk2
	✅ 🧪 api-ios	✅ 🧪 api-mac	✅ 🧪 api-gtk
	✅ 🛠 tv	✅ 🧪 mac-wk1
	✅ 🛠 tv-sim	✅ 🧪 mac-wk2
	✅ 🛠 watch	✅ 🧪 mac-AS-debug-wk2
✅ 🛠 🧪 unsafe-merge	✅ 🛠 watch-sim	✅ 🧪 mac-wk2-stress

[webkit-early-warning-system]

EWS run on current version of this PR (hash c2113f2)

Misc	iOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 🧪 win
✅ 🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-debug	✅ 🛠 gtk	✅ 🛠 wincairo
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	✅ 🛠 mac-AS-debug	✅ 🧪 gtk-wk2
	✅ 🧪 api-ios	✅ 🧪 api-mac	✅ 🧪 api-gtk
	✅ 🛠 tv	✅ 🧪 mac-wk1
	✅ 🛠 tv-sim	✅ 🧪 mac-wk2
	✅ 🛠 watch	✅ 🧪 mac-AS-debug-wk2
✅ 🛠 🧪 unsafe-merge	✅ 🛠 watch-sim	✅ 🧪 mac-wk2-stress

[eric-carlson]

r=me

[webkit-commit-queue]

Committed 255057@main (f83459d): https://commits.webkit.org/255057@main

Reviewed commits have been landed. Closing PR #4843 and removing active labels.