The current code fortunately has worked so far because only BitmapImage::startAnimation calls frameIsCompleteAtIndex, and startAnimation cannot call frameIsCompleteAtIndex if ImageDecoder is not yet initialized. startAnimation returns at the first line becase shouldAnimate() always return false in this case.
if (m_frameTimer || !shouldAnimate() || frameCount() <= 1)
This change is needed because parallel image decoders call BitmapImage::frameIsCompleteAtIndex in other places too.
Created attachment 151205 [details]
Comment on attachment 151205 [details]
Clearing flags on attachment: 151205
Committed r122368: <http://trac.webkit.org/changeset/122368>
All reviewed patches have been landed. Closing bug.