Prepare to have more than one universe.

dart/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 {
-  int nextFreeClassId = 0;
   Map<Element, String> generatedCode;
   Map<Element, String> generatedBailoutCode;
   final Set<ClassElement> instantiatedClasses;
   final Set<SourceString> instantiatedClassInstanceFields;
   final Set<FunctionElement> staticFunctionsNeedingGetter;
   final Map<SourceString, Set<Selector>> invokedNames;
   final Map<SourceString, Set<Selector>> invokedGetters;
   final Map<SourceString, Set<Selector>> invokedSetters;
-  final Map<String, LibraryElement> libraries;
   // TODO(ngeoffray): This should be a Set<Type>.
   final Set<Element> isChecks;
   final RuntimeTypeInformation rti;
 
   Universe() : generatedCode = new Map<Element, String>(),
                generatedBailoutCode = new Map<Element, String>(),
-               libraries = new Map<String, LibraryElement>(),
                instantiatedClasses = new Set<ClassElement>(),
                instantiatedClassInstanceFields = new Set<SourceString>(),
                staticFunctionsNeedingGetter = new Set<FunctionElement>(),
                invokedNames = new Map<SourceString, Set<Selector>>(),
                invokedGetters = new Map<SourceString, Set<Selector>>(),
                invokedSetters = new Map<SourceString, Set<Selector>>(),
                isChecks = new Set<Element>(),
                rti = new RuntimeTypeInformation();
 
-  int getNextFreeClassId() => nextFreeClassId++;
-
   void addGeneratedCode(WorkItem work, String code) {
     generatedCode[work.element] = code;
   }
 
   void addBailoutCode(WorkItem work, String code) {
     generatedBailoutCode[work.element] = code;
   }
 
   bool hasMatchingSelector(Set<Selector> selectors,
                            Element member,
                            Compiler compiler) {
     if (selectors === null) return false;
     for (Selector selector in selectors) {
       if (selector.applies(member, compiler)) return true;
     }
     return false;
   }
 
   bool hasInvocation(Element member, Compiler compiler) {
-    return hasMatchingSelector(
-        compiler.universe.invokedNames[member.name], member, compiler);
+    return hasMatchingSelector(invokedNames[member.name], member, compiler);
   }
 
   bool hasGetter(Element member, Compiler compiler) {
-    return hasMatchingSelector(
-        compiler.universe.invokedGetters[member.name], member, compiler);
+    return hasMatchingSelector(invokedGetters[member.name], member, compiler);
   }
 
   bool hasSetter(Element member, Compiler compiler) {
-    return hasMatchingSelector(
-        compiler.universe.invokedSetters[member.name], member, compiler);
+    return hasMatchingSelector(invokedSetters[member.name], member, compiler);
   }
 }
 
 class SelectorKind {
   final String name;
   const SelectorKind(this.name);
 
   static final SelectorKind GETTER = const SelectorKind('getter');
   static final SelectorKind SETTER = const SelectorKind('setter');
   static final SelectorKind INVOCATION = const SelectorKind('invocation');
@@ skipping 266 matching lines @@
 
     return false;
   }
 
   bool operator ==(other) {
     if (other is !TypedSelector) return false;
     if (other.receiverType !== receiverType) return false;
     return super == other;
   }
 }