Don't assume that a transform node is consistently deferred or not.

pkg/barback/lib/src/phase_input.dart

Index: pkg/barback/lib/src/phase_input.dart
diff --git a/pkg/barback/lib/src/phase_input.dart b/pkg/barback/lib/src/phase_input.dart
index 929e96740d6cd63c405e0999f6b6829f971460fc..bd47f1a863b756cce2d0d24b6f0451f89429018a 100644
--- a/pkg/barback/lib/src/phase_input.dart
+++ b/pkg/barback/lib/src/phase_input.dart
@@ -50,7 +50,7 @@ class PhaseInput {
 
   /// How far along [this] is in processing its assets.
   NodeStatus get status {
-    var status = input.state.isDirty && !input.deferred ?
+    var status = input.state.isDirty && !input.isLazy ?
         NodeStatus.MATERIALIZING : NodeStatus.IDLE;
     return status.dirtier(NodeStatus.dirtiest(
         _transforms.map((transform) => transform.status)));