Reapply Issue 10911006.

lib/compiler/implementation/universe.dart

 // Copyright (c) 2012, 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.
 
 class Universe {
   Map<Element, CodeBuffer> generatedCode;
   Map<Element, CodeBuffer> generatedBailoutCode;
   final Set<ClassElement> instantiatedClasses;
   final Set<FunctionElement> staticFunctionsNeedingGetter;
   final Map<SourceString, Set<Selector>> invokedNames;
   final Map<SourceString, Set<Selector>> invokedGetters;
   final Map<SourceString, Set<Selector>> invokedSetters;
   final Map<SourceString, Set<Selector>> fieldGetters;
   final Map<SourceString, Set<Selector>> fieldSetters;
-  // TODO(ngeoffray): This should be a Set<DartType>.
-  final Set<Element> isChecks;
+  final Set<DartType> isChecks;
+  // TODO(karlklose): move this data to RuntimeTypeInformation.
+  Set<Element> checkedClasses;
   final RuntimeTypeInformation rti;
 
   Universe() : generatedCode = new Map<Element, CodeBuffer>(),
                generatedBailoutCode = new Map<Element, CodeBuffer>(),
                instantiatedClasses = new Set<ClassElement>(),
                staticFunctionsNeedingGetter = new Set<FunctionElement>(),
                invokedNames = new Map<SourceString, Set<Selector>>(),
                invokedGetters = new Map<SourceString, Set<Selector>>(),
                invokedSetters = new Map<SourceString, Set<Selector>>(),
                fieldGetters = new Map<SourceString, Set<Selector>>(),
                fieldSetters = new Map<SourceString, Set<Selector>>(),
-               isChecks = new Set<Element>(),
+               isChecks = new Set<DartType>(),
                rti = new RuntimeTypeInformation();
 
+  // TODO(karlklose): add the set of instantiatedtypes as second argument.
+  void computeRequiredTypes(Set<DartType> isChecks) {
+    assert(checkedClasses == null);
+    checkedClasses = new Set<Element>();
+    isChecks.forEach((DartType t) => checkedClasses.add(t.element));
+  }
+
   void addGeneratedCode(WorkItem work, CodeBuffer codeBuffer) {
     generatedCode[work.element] = codeBuffer;
   }
 
   void addBailoutCode(WorkItem work, CodeBuffer codeBuffer) {
     generatedBailoutCode[work.element] = codeBuffer;
   }
 
   bool hasMatchingSelector(Set<Selector> selectors,
                            Element member,
@@ skipping 357 matching lines @@
 
     if (!self.isInterface() && self.isSubclassOf(other)) {
       // Resolve an invocation of [element.name] on [self]. If it
       // is found, this selector is a candidate.
       return hasElementIn(self, element) && appliesUntyped(element, compiler);
     }
 
     return false;
   }
 }