dart2dart: Use implicit 'this' when generating Dart code.

sdk/lib/_internal/compiler/implementation/dart_backend/dart_tree_printer.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library dart_tree_printer;
 
 import 'dart_printer.dart';
 import '../tree/tree.dart' as tree;
 import '../scanner/scannerlib.dart';
 import '../util/util.dart';
@@ skipping 308 matching lines @@
       }
       result = new tree.Send(
           receiver,
           selector,
           argList(exp.arguments.map(makeArgument)));
       if (callee is Identifier) {
         setElement(result, element, exp);
       }
     } else if (exp is CallMethod) {
       precedence = CALLEE;
+      tree.Node receiver = exp.object is This
+          ? null
+          : makeExp(exp.object, PRIMARY, beginStmt: beginStmt);
       result = new tree.Send(
-          makeExp(exp.object, PRIMARY, beginStmt: beginStmt),
+          receiver,
           makeIdentifier(exp.methodName),
           argList(exp.arguments.map(makeArgument)));
     } else if (exp is CallNew) {
       precedence = CALLEE;
       tree.Node selector = makeName(exp.type.name);
       if (exp.type.typeArguments.length > 0) {
         selector = new tree.TypeAnnotation(
             selector,
             typeArgList(exp.type.typeArguments.map(makeType)));
         setType(selector, exp.dartType, exp);
@@ skipping 22 matching lines @@
     } else if (exp is Conditional) {
       precedence = CONDITIONAL;
       result = new tree.Conditional(
           makeExp(exp.condition, LOGICAL_OR, beginStmt: beginStmt),
           makeExp(exp.thenExpression, EXPRESSION),
           makeExp(exp.elseExpression, EXPRESSION),
           question,
           colon);
     } else if (exp is FieldExpression) {
       precedence = PRIMARY;
-      result = new tree.Send(
-          makeExp(exp.object, PRIMARY, beginStmt: beginStmt),
-          makeIdentifier(exp.fieldName));
+      tree.Node receiver = exp.object is This
+          ? null
+          : makeExp(exp.object, PRIMARY, beginStmt: beginStmt);
+      result = new tree.Send(receiver, makeIdentifier(exp.fieldName));
     } else if (exp is FunctionExpression) {
       precedence = PRIMARY;
       if (beginStmt && exp.name != null) {
         needParen = true; // Do not mistake for function declaration.
       }
       // exp.element can only be null in tests.
       tree.Node body = exp.element != null &&
           exp.element.node.body is tree.EmptyStatement
         ? exp.element.node.body
         : makeFunctionBody(exp.body);
@@ skipping 622 matching lines @@
             printStringChunk(chunk.previous),
             node);
       } else {
         return node;
       }
     }
     return printStringChunk(output.chunk);
   }
 
 }