Add TypeUse.

pkg/compiler/lib/src/resolution/signatures.dart

Index: pkg/compiler/lib/src/resolution/signatures.dart
diff --git a/pkg/compiler/lib/src/resolution/signatures.dart b/pkg/compiler/lib/src/resolution/signatures.dart
index 94ebf43b50f4e178aeffddda8cb111bccceba0f8..df165a698898b86ffeb36c49b0046dea7d14f2f6 100644
--- a/pkg/compiler/lib/src/resolution/signatures.dart
+++ b/pkg/compiler/lib/src/resolution/signatures.dart
@@ -18,6 +18,8 @@ import '../elements/modelx.dart' show
     InitializingFormalElementX,
     LocalParameterElementX;
 import '../tree/tree.dart';
+import '../universe/use.dart' show
+    TypeUse;
 import '../util/util.dart' show
     Link,
     LinkBuilder;
@@ -341,7 +343,7 @@ class SignatureResolver extends MappingVisitor<FormalElementX> {
       // Because there is no type annotation for the return type of
       // this element, we explicitly add one.
       if (compiler.enableTypeAssertions) {
-        registry.registerIsCheck(returnType);
+        registry.registerTypeUse(new TypeUse.checkedModeCheck(returnType));
       }
     } else {
       AsyncMarker asyncMarker = AsyncMarker.SYNC;