GPU-GPU copy of video textures to WebGL has been added for GStreamer in bug 159928. It did not handle videos with inverted Y, and thus copy of such videos is not accelerated. This occurs for example on http://flimshaw.github.io/Valiant360/
This occurs with apps using THREE.js, which defaults to flipY for textures.
Created attachment 289684 [details] Patch
Comment on attachment 289684 [details] Patch Clearing flags on attachment: 289684 Committed r206369: <http://trac.webkit.org/changeset/206369>
All reviewed patches have been landed. Closing bug.