Fix type errors.

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");
 #import("scanner/scannerlib.dart");  // Scanner, Parsers, Listeners
 #import("elements/elements.dart");
 #import('native_handler.dart', prefix: 'native');
 
 class PatchParserTask extends leg.CompilerTask {
   PatchParserTask(leg.Compiler compiler): super(compiler);
   final String name = "Patching Parser";
 
   LibraryElement loadPatchLibrary(Uri uri) {
     bool newLibrary = false;
-    PatchLibraryElement library =
+    LibraryElement library =
       compiler.libraries.putIfAbsent(uri.toString(), () {
           newLibrary = true;
           leg.Script script = compiler.readScript(uri, null);
           LibraryElement element =
               new LibraryElement(script);
           native.maybeEnableNative(compiler, element, uri);
           return element;
         });
     if (newLibrary) {
       compiler.withCurrentElement(library, () {
@@ skipping 96 matching lines @@
   Token parseClassBody(Token token) => fullParseClassBody(token);
 }
 
 
 /**
  * Extension of [ElementListener] for parsing patch files.
  */
 class PatchElementListener extends ElementListener implements PatchListener {
   bool isMemberPatch = false;
   bool isClassPatch = false;
-  PatchElementListener(DiagnosticListener listener,
+  PatchElementListener(leg.DiagnosticListener listener,
                        CompilationUnitElement patchElement,
                        int idGenerator())
     : super(listener, patchElement, idGenerator);
 
   void beginPatch(Token token) {
     if (token.next.stringValue === "class") {
       isClassPatch = true;
     } else {
       isMemberPatch = true;
     }
     handleIdentifier(token);
   }
 
   void endPatch(Token token) {
     if (token.next.stringValue === "class") {
       isClassPatch = false;
     } else {
       isMemberPatch = false;
     }
   }
 
   void pushElement(Element element) {
     if (isMemberPatch || (isClassPatch && element is ClassElement)) {
       element.addMetadata(popNode());
     }
     super.pushElement(element);
   }
 }