Chinmay Garde df53c9f095 Ensure that the CAMetalLayer FBO attachments can be read from. (flutter/engine#13643)
By default, the CAMetalLayer backing store is a framebuffer attachment that is
only optimized for display. However, effects such as backdrop filters require
renderbuffer readback. Making this calls will result in exceptions. Disable the
write only optimization on such backing store.

Fixes https://github.com/flutter/flutter/issues/43555
2019-11-04 17:28:51 -08:00
..