Disable dart2js hints by default.

pkg/analyzer/lib/src/generated/engine.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;
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:math' as math;
 
@@ skipping 6226 matching lines @@
   /**
    * The maximum number of sources for which AST structures should be kept in
    * the cache.
    */
   int cacheSize = DEFAULT_CACHE_SIZE;
 
   /**
    * A flag indicating whether analysis is to generate dart2js related hint
    * results.
    */
-  bool dart2jsHint = true;
+  bool dart2jsHint = false;
 
   /**
    * A flag indicating whether generic methods are to be supported (DEP 22).
    */
   bool enableGenericMethods = false;
 
   /**
    * A flag indicating whether analysis is to strictly follow the specification
    * when generating warnings on "call" methods (fixes dartbug.com/21938).
    */
@@ skipping 5665 matching lines @@
     PendingFuture pendingFuture =
         new PendingFuture<T>(_context, source, computeValue);
     if (!pendingFuture.evaluate(sourceEntry)) {
       _context._pendingFutureSources
           .putIfAbsent(source, () => <PendingFuture>[])
           .add(pendingFuture);
     }
     return pendingFuture.future;
   }
 }