HW compositing was turned off for Leopard due to a Core Video bug. This caused crashes sometimes with Video on a HW compositing layer. We could turn it back on if WebGL is turned on. This would limit the exposure of the Core Video bug to those who have opted in to WebGL in a nightly build.
This is related to: https://bugs.webkit.org/show_bug.cgi?id=35338.
Seems fine. I would word this as:
"When WebGL is enabled, enable hardware compositing bypassing check for CoreVideo bug fix"
Or something like that.
Created attachment 50248 [details]
Landed in http://trac.webkit.org/changeset/55685