Revert r27592, some unit tests fail.

sdk/lib/_internal/compiler/implementation/types/concrete_types_inferrer.dart

Index: sdk/lib/_internal/compiler/implementation/types/concrete_types_inferrer.dart
===================================================================
--- sdk/lib/_internal/compiler/implementation/types/concrete_types_inferrer.dart	(revision 27592)
+++ sdk/lib/_internal/compiler/implementation/types/concrete_types_inferrer.dart	(working copy)
@@ -1666,7 +1666,7 @@
                       ConcreteTypesInferrer inferrer, this.environment)
       : this.inferrer = inferrer
       , this.backend = inferrer.compiler.backend
-      , super(elements, inferrer.compiler) {
+      , super(elements) {
         for (Element element in elements.otherDependencies) {
           if (element.isClass()) {
             inferrer.augmentSeenClasses(inferrer.normalize(element));
@@ -2378,14 +2378,6 @@
     return inferrer.unknownConcreteType;
   }
 
-  ConcreteType visitAssert(Send node) {
-    if (!compiler.enableUserAssertions) {
-      return inferrer.nullConcreteType;
-    } else {
-      return visitStaticSend(node);
-    }
-  }
-
   ConcreteType visitStaticSend(Send node) {
     if (elements.getSelector(node).name == const SourceString('JS')) {
       return inferrer.getNativeCallReturnType(node);