dart2js: Use an abstract Name class for names in the generated JavaScript ast.

pkg/compiler/lib/src/js_emitter/old_emitter/declarations.dart

 // Copyright (c) 2013, 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.
 
 part of dart2js.js_emitter;
 
 /// Enables debugging of fast/slow objects using V8-specific primitives.
 const DEBUG_FAST_OBJECTS = false;
 
 /**
  * Call-back for adding property with [name] and [value].
  */
-typedef jsAst.Property AddPropertyFunction(String name, jsAst.Expression value);
+typedef jsAst.Property AddPropertyFunction(jsAst.Name name,
+                                           jsAst.Expression value);
 
 /**
  * [member] is a field (instance, static, or top level).
  *
  * [name] is the field name that the [Namer] has picked for this field's
  * storage, that is, the JavaScript property name.
  *
  * [accessorName] is the name of the accessor. For instance fields this is
  * mostly the same as [name] except when [member] is shadowing a field in its
  * superclass.  For other fields, they are rarely the same.
  *
  * [needsGetter] and [needsSetter] represent if a getter or a setter
  * respectively is needed.  There are many factors in this, for example, if the
  * accessor can be inlined.
  *
  * [needsCheckedSetter] indicates that a checked getter is needed, and in this
  * case, [needsSetter] is always false. [needsCheckedSetter] is only true when
  * type assertions are enabled (checked mode).
  */
 typedef void AcceptField(VariableElement member,
-                         String name,
-                         String accessorName,
+                         jsAst.Name name,
+                         jsAst.Name accessorName,
                          bool needsGetter,
                          bool needsSetter,
                          bool needsCheckedSetter);
 
 // Function signatures used in the generation of runtime type information.
 typedef void FunctionTypeSignatureEmitter(Element method,
                                           FunctionType methodType);
 
 typedef void SubstitutionEmitter(Element element, {bool emitNull});
 
@@ skipping 34 matching lines @@
 // characters.
 const FIELD_CODE_CHARACTERS = r"<=>?@{|}~%&'()*";
 const NO_FIELD_CODE = 0;
 const FIRST_FIELD_CODE = 1;
 const RANGE1_FIRST = 0x3c;   //  <=>?@    encodes 1..5
 const RANGE1_LAST = 0x40;
 const RANGE2_FIRST = 0x7b;   //  {|}~     encodes 6..9
 const RANGE2_LAST = 0x7e;
 const RANGE3_FIRST = 0x25;   //  %&'()*+  encodes 10..16
 const RANGE3_LAST = 0x2b;