debugStripZoomReplayBackendOverride property
Test hook for the shader-capability half of the backend gate:
flutter test runs on software Skia where
ui.ImageFilter.isShaderFilterSupported is false, so strip router tests
force the decision. The iOS safety gate still applies when this is true.
Null (production) asks the engine.
Implementation
static bool? debugStripZoomReplayBackendOverride;