Using Scene.toGpuImage seems to aggressively trigger GC during frame workload #106698
Description
When running through some benchmarks with the timeline enabled, I've noticed that pretty much every call to Scene.toGpuImage results in a GC:
According to @dnfield this is expected, because Dart may need to reduce PSS size before allocating the large texture.
(The ui.Image created by Scene.toGpuImage and Picture.toImage reports an estimation of its external size as 4 * width * height to Dart: https://github.com/flutter/engine/pull/33736/files#diff-44a029b47e68b6b14a22356aef963e5f11bbd67e906c4d38fdef67153ba211a2R46-R52)
Generally triggering a GC during a frame workload is bad.