Add helpers library to dart2js.

tests/compiler/dart2js/analyze_helper.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.
 
 library analyze_helper;
 
 import 'dart:async';
 import 'dart:io';
 import '../../../sdk/lib/_internal/compiler/compiler.dart' as api;
 import '../../../sdk/lib/_internal/compiler/implementation/apiimpl.dart';
@@ skipping 65 matching lines @@
       }
     }
   }
 
   bool checkWhiteList(Uri uri, String message) {
     if (uri == null) {
       return false;
     }
     String path = uri.path;
     for (String file in whiteListMap.keys) {
-      if (path.endsWith(file)) {
+      if (path.contains(file)) {
         for (String messagePart in whiteListMap[file].keys) {
           if (message.contains(messagePart)) {
             whiteListMap[file][messagePart]++;
             return true;
           }
         }
       }
     }
     return false;
   }
@@ skipping 25 matching lines @@
       hasErrors = true;
     }
     if (kind == api.Diagnostic.INFO && lastWasWhitelisted) {
       return;
     }
     lastWasWhitelisted = false;
     super.diagnosticHandler(uri, begin, end, message, kind);
   }
 }
 
+typedef bool CheckResults(Compiler compiler,
+                          CollectingDiagnosticHandler handler);
+
 Future analyze(List<Uri> uriList,
                Map<String, List<String>> whiteList,
-               {bool analyzeAll: true}) {
+               {bool analyzeAll: true,
+                CheckResults checkResults}) {
   String testFileName =
       relativize(Uri.base, Platform.script, Platform.isWindows);
 
   print("""
 
 
 === 
 === NOTE: If this test fails, update [WHITE_LIST] in $testFileName
 ===
 
@@ skipping 16 matching lines @@
 
 
 === 
 === ERROR: Unexpected result of analysis.
 === 
 === Please update [WHITE_LIST] in $testFileName
 === 
 """;
 
   void onCompletion(_) {
-    bool result = handler.checkResults();
+    bool result;
+    if (checkResults != null) {
+      result = checkResults(compiler, handler);
+    } else {
+      result = handler.checkResults();
+    }
     if (!result) {
       print(MESSAGE);
       exit(1);
     }
   }
   if (analyzeAll) {
     compiler.librariesToAnalyzeWhenRun = uriList;
     return compiler.run(null).then(onCompletion);
   } else {
     return compiler.run(uriList.single).then(onCompletion);
   }
 }