* Revert "Add flow test fixtures and tests (#13986)"
This reverts commit 620f5281b819f304e8e9e945222e26b17b087cc3.
* Revert "Dynamically determine whether to use offscreen surface based on need (#13976)"
This reverts commit a86ef946563b020108320bbfb974bf7343284fd3.
This reverts commit f456423cfb820d07bb36e9a8979e3d75cc9d8d76.
This is being reverted because it caused flutter/flutter#45098
(images don't load on iOS).
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
