Remove most superfluous getter arguments from dart2js.

dart/lib/compiler/implementation/patch_parser.dart

 // Copyright (c) 2012, 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("patchparser");
 #import("dart:uri");
 
 #import("tree/tree.dart", prefix: "tree");
 #import("leg.dart", prefix: 'leg');  // CompilerTask, Compiler.
 #import("apiimpl.dart");
@@ skipping 77 matching lines @@
   void endPatch(Token patch);
 }
 
 /**
  * Partial parser that extends the top-level and class grammars to allow the
  * word "patch" in front of some declarations.
  */
 class PatchParser extends PartialParser {
   PatchParser(PatchListener listener) : super(listener);
 
-  PatchListener get patchListener() => listener;
+  PatchListener get patchListener => listener;
 
   bool isPatch(Token token) {
     return token.stringValue === null &&
            token.slowToString() == "patch";
   }
 
   /**
    * Parse top-level declarations, and allow "patch" in front of functions
    * and classes.
    */
@@ skipping 170 matching lines @@
     }
   }
 
   void addMember(Element element) {
     if (isMemberPatch || (isClassPatch && element is ClassElement)) {
       element.addMetadata(popNode());
     }
     super.addMember(element);
   }
 }