This proposal is to add an event that would fire on a content-visibility: auto element when the rendering state of the element changes due to any of the attributes that make the element relevant to the user (https://www.w3.org/TR/css-contain-2/#relevant-to-the-user)
The use-case for this is to let developers have greater control over when to stop or start rendering in response to the user-agent stopping or starting rendering of the content-visibility subtree. For example, the developer may want to stop React updates in a subtree that is not rendered by the user-agent. Similarly, the developer may want to stop any other script updates (e.g. canvas updates) when the user-agent is not rendering the element.
Initial public proposal
TAG review status
Interoperability and Compatibility
WebView application risks
Does this intent deprecate or change behavior of existing APIs, such that it has potentially high risk for Android WebView-based applications?
This feature can be debugged similarly to other events
Requires code in //chrome?
No milestones specified
Link to entry on the Chrome Platform Status