Add optional message to assert in Dart2js.

pkg/compiler/lib/src/inferrer/inferrer_visitor.dart

Index: pkg/compiler/lib/src/inferrer/inferrer_visitor.dart
diff --git a/pkg/compiler/lib/src/inferrer/inferrer_visitor.dart b/pkg/compiler/lib/src/inferrer/inferrer_visitor.dart
index ab77d7b8bec4f95d44314233d23993fcc4460d44..8e6cccc7a714b6af5442f2c4e5f247a8de007bec 100644
--- a/pkg/compiler/lib/src/inferrer/inferrer_visitor.dart
+++ b/pkg/compiler/lib/src/inferrer/inferrer_visitor.dart
@@ -782,17 +782,7 @@ abstract class InferrerVisitor<T, E extends MinimalInferrerEngine<T>>
     return handleSendSet(node);
   }
 
-  @override
-  T visitAssert(Send node, Node expression, _) {
-    if (!compiler.enableUserAssertions) {
-      return types.nullType;
-    }
-    return handleAssert(node, expression);
-  }
-
   /// Handle an enabled assertion of [expression].

[Johnni Winther, 2015/09/01 13:32:05]

Remove as well.

[Lasse Reichstein Nielsen, 2015/09/03 11:23:25]

Done.

-  T handleAssert(Send node, Node expression);
-
   T visitNode(Node node) {
     return node.visitChildren(this);
   }