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

pkg/compiler/lib/src/dart_backend/backend_ast_to_frontend_ast.dart

Index: pkg/compiler/lib/src/dart_backend/backend_ast_to_frontend_ast.dart
diff --git a/pkg/compiler/lib/src/dart_backend/backend_ast_to_frontend_ast.dart b/pkg/compiler/lib/src/dart_backend/backend_ast_to_frontend_ast.dart
index 7c8113a26352b6a03ffbd573b6188983b8909ad7..9bf9121c02e18cbb382d30a3687e696726236340 100644
--- a/pkg/compiler/lib/src/dart_backend/backend_ast_to_frontend_ast.dart
+++ b/pkg/compiler/lib/src/dart_backend/backend_ast_to_frontend_ast.dart
@@ -398,9 +398,9 @@ class TreePrinter {
       }
     } else if (exp is CallMethod) {
       precedence = CALLEE;
-      tree.Node receiver = exp.object is This
-          ? null
-          : makeExp(exp.object, PRIMARY, beginStmt: beginStmt);
+      // TODO(sra): Elide receiver when This, but only if not in a scope that
+      // shadows the method (e.g. constructor body).
+      tree.Node receiver = makeExp(exp.object, PRIMARY, beginStmt: beginStmt);
       result = new tree.Send(
           receiver,
           makeIdentifier(exp.methodName),
@@ -445,9 +445,9 @@ class TreePrinter {
           colon);
     } else if (exp is FieldExpression) {
       precedence = PRIMARY;
-      tree.Node receiver = exp.object is This
-          ? null
-          : makeExp(exp.object, PRIMARY, beginStmt: beginStmt);
+      // TODO(sra): Elide receiver when This, but only if not in a scope that
+      // shadows the method (e.g. constructor body).
+      tree.Node receiver = makeExp(exp.object, PRIMARY, beginStmt: beginStmt);
       result = new tree.Send(receiver, makeIdentifier(exp.fieldName));
     } else if (exp is ConstructorDefinition) {
       precedence = EXPRESSION;