I had added this initially as a means of making it easier to deal with OpenGL directly in Flow. However, we are moving away from dealing with the client rendering APIs directly. Instead, delegating everything to Skia. Besides, we only ever used this to log the GPU description in case of context setup failures. This has not proved to be useful so far. Also, having this in place is making it difficult to remove all dependencies on GL in Shell.
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.
