All strong mode cleaning of dart2js.

pkg/compiler/lib/src/js_emitter/runtime_type_generator.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.js_emitter.runtime_type_generator;
 
 import '../closure.dart'
     show ClosureRepresentationInfo, ClosureFieldElement, ClosureConversionTask;
 import '../common.dart';
 import '../common/names.dart' show Identifiers;
@@ skipping 159 matching lines @@
       ClassElement checkedClass = check.cls;
       generateIsTest(checkedClass);
       Substitution substitution = check.substitution;
       if (substitution != null) {
         jsAst.Expression body =
             _rtiEncoder.getSubstitutionCode(emitterTask.emitter, substitution);
         result.properties[_namer.substitutionName(checkedClass)] = body;
       }
     }
 
-    _generateIsTestsOn(classElement, generateIsTest,
-        generateFunctionTypeSignature, generateSubstitution, generateTypeCheck);
+    _generateIsTestsOn(classElement, (Element e) {
+      generateIsTest(e);
+    }, (Element e, ResolutionFunctionType t) {
+      generateFunctionTypeSignature(e, t);
+    },
+        (Element e, {bool emitNull: false}) =>
+            generateSubstitution(e, emitNull: emitNull),
+        generateTypeCheck);
 
     if (classElement == _commonElements.jsJavaScriptFunctionClass) {
       var type = _jsInteropAnalysis.buildJsFunctionType();
       if (type != null) {
         jsAst.Expression thisAccess = new jsAst.This();
         jsAst.Expression encoding = _rtiEncoder.getSignatureEncoding(
             emitterTask.emitter, type, thisAccess);
         jsAst.Name operatorSignature = _namer.asName(_namer.operatorSignature);
         result.properties[operatorSignature] = encoding;
       }
@@ skipping 142 matching lines @@
 
     // We need to also emit "is checks" for the superclass and its supertypes.
     ClassElement superclass = cls.superclass;
     if (superclass != null) {
       tryEmitTest(superclass);
       _generateInterfacesIsTests(
           superclass, generateIsTest, generateSubstitution, alreadyGenerated);
     }
   }
 }