When releasing a resize in full screen video, the video content briefly flashes to its original size

[rr-codes]

0de5d9c

When releasing a resize in full screen video, the video content briefly flashes to its original size
https://bugs.webkit.org/show_bug.cgi?id=260558
rdar://113771996

Reviewed by Tim Horton.

When releasing a resize of a window on visionOS that contains a fixed-position element, the element's size
briefly becomes its original size.

In `_endLiveResize`, we create a snapshot view and put it on top of the web content. The snapshot is then
removed in the completion handler of a `doAfterNextPresentationUpdate` call.

However, by the time the transaction commit happens in the presentation update, two important
updates have yet to happen:
1. A visible content rect update
2. A geometry update

The visible content rect update needs to happen before the commit so that all the new sizes are updated.
However, `doAfterNextPresentationUpdate` does not ensure this. To fix, bundle a VCR update inside the
`UpdateGeometry` message, and then have the web page update the VCRs when receiving the message.

The geometry update of the drawing area was not happening because its size was never being set. When a
geometry uodate is deferred, `_frameOrBoundsMayHaveChanged` skips setting all the relevant new values.
Instead, all these values are (theoretically) set in `_didStopDeferringGeometryUpdates`. However,
`_didStopDeferringGeometryUpdates` was missing setting the size of the drawing area.

As a result, in `sendUpdateGeometry`, the layout size and other changes were being updated, but the
drawing area size was the old value. It then eventually does get updated on the next UIKit layout via
`frameOrBoundsMayHaveChanged`, but by that point the snapshot view has already been removed.

Fix by simply ensuring that `_didStopDeferringGeometryUpdates` also updates the drawing area size.

* Source/WebKit/UIProcess/API/ios/WKWebViewIOS.h:
* Source/WebKit/UIProcess/API/ios/WKWebViewIOS.mm:
(-[WKWebView _createVisibleRectUpdateInfo]):
(-[WKWebView _didStopDeferringGeometryUpdates]):
* Source/WebKit/UIProcess/PageClient.h:
* Source/WebKit/UIProcess/RemoteLayerTree/RemoteLayerTreeDrawingAreaProxy.h:
(WebKit::RemoteLayerTreeDrawingAreaProxy::setLastVisibleContentRectUpdate):
(WebKit::RemoteLayerTreeDrawingAreaProxy::lastVisibleContentRectUpdate const):
* Source/WebKit/UIProcess/RemoteLayerTree/RemoteLayerTreeDrawingAreaProxy.mm:
(WebKit::RemoteLayerTreeDrawingAreaProxy::sendUpdateGeometry):
* Source/WebKit/UIProcess/ios/PageClientImplIOS.h:
* Source/WebKit/UIProcess/ios/PageClientImplIOS.mm:
(WebKit::PageClientImpl::createVisibleRectUpdateInfo):
* Source/WebKit/UIProcess/ios/WKContentView.h:
* Source/WebKit/UIProcess/ios/WKContentView.mm:
(-[WKContentView createVisibleRectUpdateInfoFromVisibleRect:unobscuredRect:contentInsets:unobscuredRectInScrollViewCoordinates:obscuredInsets:unobscuredSafeAreaInsets:inputViewBounds:scale:minimumScale:viewStability:enclosedInScrollableAncestorView:sendEvenIfUnchanged:]):
(-[WKContentView didUpdateVisibleRect:unobscuredRect:contentInsets:unobscuredRectInScrollViewCoordinates:obscuredInsets:unobscuredSafeAreaInsets:inputViewBounds:scale:minimumScale:viewStability:enclosedInScrollableAncestorView:sendEvenIfUnchanged:]):
* Source/WebKit/UIProcess/ios/WebPageProxyIOS.mm:
* Source/WebKit/WebProcess/WebPage/DrawingArea.h:
* Source/WebKit/WebProcess/WebPage/DrawingArea.messages.in:
* Source/WebKit/WebProcess/WebPage/RemoteLayerTree/RemoteLayerTreeDrawingArea.h:
* Source/WebKit/WebProcess/WebPage/RemoteLayerTree/RemoteLayerTreeDrawingArea.mm:
(WebKit::RemoteLayerTreeDrawingArea::updateGeometry):

Canonical link: https://commits.webkit.org/267652@main

d3311a1

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

[webkit-early-warning-system]

EWS run on current version of this PR (hash d3311a1)

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

[mwyrzykowski]

is this change needed?

[mwyrzykowski]

Do we send an UpdateGeometry message when the window size does not change?

I am wondering if we should only be sending this visibleRectUpdateInfo when the window size changes to avoid a potential performance regression on iOS? @hortont424 do you know?

Or will we always early return if duplicate visibleRectUpdateInfo are sent? Its not immediately clear to me looking at the implementation of WebPage::updateVisibleContentRects

[rr-codes]

Seems like there's an early return in DrawingAreaProxy::setSize
(which is upstream of sendUpdateGeometry), so I think it's fine.

[webkit-commit-queue]

Committed 267652@main (0de5d9c): https://commits.webkit.org/267652@main

Reviewed commits have been landed. Closing PR #17448 and removing active labels.