The GPUSurfaceGL holds references to Skia objects that may own GL objects.
If the GL objects are destructed on the GPU thread after the EGL context has been
dropped, then the GL delete calls will not take effect.
* Update Skia revision to pull in GL native interface construction fixes on iOS.
Fixed in https://skia-review.googlesource.com/c/5212/
* Use the new image encoder API from Skia.