Add optional message to assert in Dart2js.

pkg/compiler/lib/src/resolution/registry.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 dart2js.resolution.registry;
 
 import '../common/backend_api.dart' show
     Backend;
 import '../common/registry.dart' show
     Registry;
@@ skipping 37 matching lines @@
 
   ResolutionEnqueuer get world => compiler.enqueuer.resolution;
 
   @override
   bool get isForResolution => true;
 
   @override
   Iterable<Element> get otherDependencies => mapping.otherDependencies;
 
   @override
+  void registerAssert(bool hasMessage) {
+    // TODO(johnniwinther): Do something here?
+  }
+
+  @override
   void registerDependency(Element element) {
     mapping.registerDependency(element);
   }
 
   @override
   void registerDynamicGetter(UniverseSelector selector) {
     world.registerDynamicGetter(selector);
   }
 
   @override
@@ skipping 508 matching lines @@
     // [registerDependency].
     if (element == null) return;
     registerStaticUse(element);
     registerDependency(element);
   }
 
   void registerInstantiation(InterfaceType type) {
     world.registerInstantiatedType(type, this);
   }
 
-  void registerAssert(Send node) {
-    mapping.setAssert(node);
-    backend.resolutionCallbacks.onAssert(node, this);
-  }
-
-  bool isAssert(Send node) {
-    return mapping.isAssert(node);
+  void registerAssert(bool hasMessage) {
+    backend.resolutionCallbacks.onAssert(hasMessage, this);
   }
 
   void registerSendStructure(Send node, SendStructure sendStructure) {
     mapping.setSendStructure(node, sendStructure);
   }
 
   // TODO(johnniwinther): Remove this when [SendStructure]s are part of the
   // [ResolutionResult].
   SendStructure getSendStructure(Send node) {
     return mapping.getSendStructure(node);
   }
 
   void registerAsyncMarker(FunctionElement element) {
     backend.registerAsyncMarker(element, world, this);
   }
 
   void registerAsyncForIn(AsyncForIn node) {
     backend.resolutionCallbacks.onAsyncForIn(node, this);
   }
 
   void registerTryStatement() {
     mapping.containsTryStatement = true;
   }
 }