Native bindings to the EXT_protected_surface extension.

This extension adds a new EGL surface attribute EGL_PROTECTED_CONTENT_EXT to indicate if the content in the surface buffer is protected or not. If surface attribute EGL_PROTECTED_CONTENT_EXT is EGL_TRUE, then the surface content is only accessible to secure accesses. Any attempt to access the buffer content non-securely will fail and result in undefined behavior up to and including program termination. Also, any copy operations from the protected surface to any non-protected surface by GPU are considered illegal.

Requires EGL 1.4 and KHR_image_base.