Instead of only uploading the layer images when they change, the TextureMapper seems to be uploading the image during every sync. This is quite noticeable in the GTK+ port, at least.
Created attachment 140419 [details]
Comment on attachment 140419 [details]
Clearing flags on attachment: 140419
Committed r116247: <http://trac.webkit.org/changeset/116247>
All reviewed patches have been landed. Closing bug.