Use an explicit 'this' parameter instead of 'This' nodes.

pkg/compiler/lib/src/cps_ir/type_propagation.dart

Index: pkg/compiler/lib/src/cps_ir/type_propagation.dart
diff --git a/pkg/compiler/lib/src/cps_ir/type_propagation.dart b/pkg/compiler/lib/src/cps_ir/type_propagation.dart
index bdacd015367b857e01c2152b372cbf76ea9f7d32..a8b12bedb12a97f09deeddaf6955cffea01cd6fc 100644
--- a/pkg/compiler/lib/src/cps_ir/type_propagation.dart
+++ b/pkg/compiler/lib/src/cps_ir/type_propagation.dart
@@ -725,11 +725,6 @@ class _TypePropagationVisitor<T> implements Visitor {
     setValue(node, constantValue(value, typeSystem.typeOf(value)));
   }
 
-  void visitThis(This node) {
-    // TODO(karlklose): Add the type.
-    setValue(node, nonConst());
-  }
-
   void visitReifyTypeVar(ReifyTypeVar node) {
     setValue(node, nonConst(typeSystem.typeType));
   }