Bug 61867

Summary: REGRESSION: Windowed plugins don't stay precisely in place when scrolling pages that use accelerated compositing
Product: WebKit Reporter: Adam Roben (:aroben) <aroben>
Component: Layout and RenderingAssignee: Nobody <webkit-unassigned>
Status: NEW ---    
Severity: Normal CC: andersca
Priority: P2 Keywords: PlatformOnly, Regression
Version: 528+ (Nightly build)   
Hardware: PC   
OS: Windows 7   

Description Adam Roben (:aroben) 2011-06-01 09:43:11 PDT
To reproduce:

1. Go to any YouTube video
2. Type this in the URL field and press Enter: javascript:document.body.style.webkitTransform = 'translateZ(0)'
3. Scroll the page

The YouTube video drifts ever so slightly from where it's supposed to be in the page. (It's quite hard to notice.)
Comment 1 Adam Roben (:aroben) 2011-06-01 09:44:11 PDT
This is caused by the fix for bug 58054. We move the windowed plugins when we push layer changes down into CoreAnimation, but should instead move them when those changes appear on screen (which happens on a background thread).