Add optional message to assert in Dart2js.

pkg/compiler/lib/src/universe/universe.dart

Index: pkg/compiler/lib/src/universe/universe.dart
diff --git a/pkg/compiler/lib/src/universe/universe.dart b/pkg/compiler/lib/src/universe/universe.dart
index 0574af8abc2b9d3e9c12d2fd8fe517e2934b6cad..70f07c2e22ece9ea101829e2cd84d4c9ea89f71b 100644
--- a/pkg/compiler/lib/src/universe/universe.dart
+++ b/pkg/compiler/lib/src/universe/universe.dart
@@ -825,9 +825,6 @@ class Selector {
   bool get isOperator => kind == SelectorKind.OPERATOR;
   bool get isUnaryOperator => isOperator && argumentCount == 0;
 
-  /** Check whether this is a call to 'assert'. */
-  bool get isAssert => isCall && identical(name, "assert");
-
   /**
    * The member name for invocation mirrors created from this selector.
    */
@@ -881,8 +878,7 @@ class Selector {
   bool sameNameHack(Element element, World world) {
     // TODO(ngeoffray): Remove workaround checks.
     return element.isConstructor ||
-           name == element.name ||
-           name == 'assert' && world.isAssertMethod(element);
+           name == element.name;
   }
 
   bool applies(Element element, World world) {