[CP] Create framebuffer blend vertices based on the snapshot's texture size instead of coverage #149771
Description
Issue Link
Target
stable
PR Link
Changelog Description
- Fixed rendering error advanced blend is double scaled.
Impacted Users
Impeller on iOS
Impact Description
Rendering appears correct when BlendMode greater than screen is used.
Workaround
Use Skia
Risk
low
Test Coverage
yes
Validation Steps
Run attached tests.