I made a mistake in r187534, where I updated putImageData to use the Accelerate framework. The iOS path accidentally unpremultiplied the incoming data, rather than premultiplying it.
Created attachment 276201 [details]
What's the impact on the Animometer Images test?
(In reply to comment #4)
> What's the impact on the Animometer Images test?
Should be zero. We're still doing the same sets of operations, just multiplying rather than dividing. And this is iOS only.
Committed r199330: <http://trac.webkit.org/changeset/199330>