Add optional message to assert in Dart2js.

pkg/compiler/lib/src/world.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 dart2js.world;
 
 import 'closure.dart' show
     SynthesizedCallMethodElementX;
 import 'common/backend_api.dart' show
     Backend;
@@ skipping 342 matching lines @@
   final Set<Element> elementsThatCannotThrow = new Set<Element>();
 
   final Set<Element> functionsThatMightBePassedToApply =
       new Set<FunctionElement>();
 
   final Set<Element> alreadyPopulated;
 
   bool get isClosed => compiler.phase > Compiler.PHASE_RESOLVING;
 
   // Used by selectors.
-  bool isAssertMethod(Element element) {
-    return compiler.backend.isAssertMethod(element);
-  }
-
-  // Used by selectors.
   bool isForeign(Element element) {
     return compiler.backend.isForeign(element);
   }
 
   Set<ClassElement> typesImplementedBySubclassesOf(ClassElement cls) {
     return _typesImplementedBySubclasses[cls.declaration];
   }
 
   World(Compiler compiler)
       : allFunctions = new FunctionSet(compiler),
@@ skipping 249 matching lines @@
     // function expressions's element.
     // TODO(herhut): Generate classes for function expressions earlier.
     if (element is SynthesizedCallMethodElementX) {
       return getMightBePassedToApply(element.expression);
     }
     return functionsThatMightBePassedToApply.contains(element);
   }
 
   bool get hasClosedWorldAssumption => !compiler.hasIncrementalSupport;
 }