Bug 133247

Summary:	DisplayRefreshMonitorManager can only handle one kind of DisplayRefreshMonitor per PlatformDisplayID
Product:	WebKit	Reporter:	Tim Horton <thorton>
Component:	Layout and Rendering	Assignee:	Nobody <webkit-unassigned>
Status:	NEW ---
Severity:	Normal	CC:	dino, simon.fraser
Priority:	P2
Version:	528+ (Nightly build)
Hardware:	Unspecified
OS:	Unspecified

Description Tim Horton 2014-05-23 18:34:40 PDT

After bug 132794, we have different kinds of DisplayRefreshMonitors between e.g. UI-side compositing and traditional compositing.

DisplayRefreshMonitorManager is a singleton and only handles one DisplayRefreshMonitor per PlatformDisplayID.
Therefore, if you had e.g. a UI Side compositing view and a traditional compositing view on Mac, both sharing a display, and both views tried to use rAF (or whatever), one of them would lose and get the wrong kind of Monitor. This could lead to performance problems or other brokenness.

However! This is currently not a supported configuration by any means so the problem is currently purely theoretical.