Disable dart2js hints by default.

pkg/analyzer/test/generated/resolver_test.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 engine.resolver_test;
 
 import 'dart:collection';
 
 import 'package:analyzer/src/context/context.dart' as newContext;
 import 'package:analyzer/src/generated/ast.dart';
@@ skipping 3073 matching lines @@
   var p1 = new Point(0, 0);
   var p2 = new Point(10, 10);
   int n = p1 + p2;
 }''');
     computeLibrarySourceErrors(source);
     assertErrors(source, [HintCode.INVALID_ASSIGNMENT]);
     verify([source]);
   }
 
   void test_isDouble() {
+    AnalysisOptionsImpl options = new AnalysisOptionsImpl();
+    options.dart2jsHint = true;
+    resetWithOptions(options);
     Source source = addSource("var v = 1 is double;");
     computeLibrarySourceErrors(source);
     assertErrors(source, [HintCode.IS_DOUBLE]);
     verify([source]);
   }
 
   void test_isNotDouble() {
+    AnalysisOptionsImpl options = new AnalysisOptionsImpl();
+    options.dart2jsHint = true;
+    resetWithOptions(options);
     Source source = addSource("var v = 1 is! double;");
     computeLibrarySourceErrors(source);
     assertErrors(source, [HintCode.IS_NOT_DOUBLE]);
     verify([source]);
   }
 
   void test_missingReturn_async() {
     Source source = addSource('''
 import 'dart:async';
 Future<int> f() async {}
@@ skipping 11207 matching lines @@
         // check propagated type
         FunctionType propagatedType = node.propagatedType as FunctionType;
         expect(propagatedType.returnType, test.typeProvider.stringType);
       } on AnalysisException catch (e, stackTrace) {
         thrownException[0] = new CaughtException(e, stackTrace);
       }
     }
     return null;
   }
 }