Fix other tests in 'try' after elementvisitor changes

site/try/poi/poi.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 trydart.poi;
 
 import 'dart:async' show
     Completer,
     Future;
 
@@ skipping 16 matching lines @@
 import 'package:compiler/compiler.dart' as api;
 
 import 'package:compiler/src/dart2jslib.dart' show
     Compiler,
     CompilerTask,
     Enqueuer,
     QueueFilter,
     WorkItem;
 
 import 'package:compiler/src/elements/visitor.dart' show
-    ElementVisitor;
+    BaseElementVisitor;
 
 import 'package:compiler/src/elements/elements.dart' show
     AbstractFieldElement,
     ClassElement,
     CompilationUnitElement,
     Element,
     ElementCategory,
     FunctionElement,
     LibraryElement,
     ScopeContainerElement;
@@ skipping 437 matching lines @@
     if (poiCount != null) poiCount++;
     if (success != true) {
       throw 'Compilation failed';
     }
     return findPosition(position, cachedCompiler.mainApp);
   });
 }
 
 Element findPosition(int position, Element element) {
   FindPositionVisitor visitor = new FindPositionVisitor(position, element);
-  element.accept(visitor);
+  element.accept(visitor, null);
   return visitor.element;
 }
 
 String scopeInformation(Element element, int position) {
   ScopeInformationVisitor visitor =
       new ScopeInformationVisitor(cachedCompiler, element, position);
-  element.accept(visitor);
+  element.accept(visitor, null);
   return '${visitor.buffer}';
 }
 
-class FindPositionVisitor extends ElementVisitor {
+class FindPositionVisitor extends BaseElementVisitor {
   final int position;
   Element element;
 
   FindPositionVisitor(this.position, this.element);
 
-  visitElement(modelx.ElementX e) {
+  visitElement(modelx.ElementX e, _) {
     DeclarationSite site = e.declarationSite;
     if (site is PartialElement) {
       if (site.beginToken.charOffset <= position &&
           position < site.endToken.next.charOffset) {
         element = e;
       }
     }
   }
 
-  visitClassElement(ClassElement e) {
+  visitClassElement(ClassElement e, _) {
     if (e is PartialClassElement) {
       if (e.beginToken.charOffset <= position &&
           position < e.endToken.next.charOffset) {
         element = e;
-        visitScopeContainerElement(e);
+        visitScopeContainerElement(e, _);
       }
     }
   }
 
-  visitScopeContainerElement(ScopeContainerElement e) {
-    e.forEachLocalMember((Element element) => element.accept(this));
+  visitScopeContainerElement(ScopeContainerElement e, _) {
+    e.forEachLocalMember((Element element) => element.accept(this, _));
   }
 }
 
 class ScriptOnlyFilter implements QueueFilter {
   final Uri script;
 
   ScriptOnlyFilter(this.script);
 
   bool checkNoEnqueuedInvokedInstanceMethods(Enqueuer enqueuer) => true;
 
   void processWorkItem(void f(WorkItem work), WorkItem work) {
     if (work.element.library.canonicalUri != script) {
       // TODO(ahe): Rather nasty hack to work around another nasty hack in
       // backend.dart. Find better solution.
       if (work.element.name != 'closureFromTearOff') {
         printWallClock('Skipped ${work.element}.');
         return;
       }
     }
     f(work);
     printWallClock('Processed ${work.element}.');
   }
 }
 
 class PoiTask extends CompilerTask {
   PoiTask(Compiler compiler) : super(compiler);
 
   String get name => 'POI';
 }