Even less reliance on Compiler.closedWorld

pkg/compiler/lib/src/js_backend/runtime_types.dart

Index: pkg/compiler/lib/src/js_backend/runtime_types.dart
diff --git a/pkg/compiler/lib/src/js_backend/runtime_types.dart b/pkg/compiler/lib/src/js_backend/runtime_types.dart
index 590e99f5ec32df5bb9d23de9eceed7dd7bda07bf..c8bc0a43283fcf63b28eab98541e701d4d9cf540 100644
--- a/pkg/compiler/lib/src/js_backend/runtime_types.dart
+++ b/pkg/compiler/lib/src/js_backend/runtime_types.dart
@@ -34,7 +34,8 @@ abstract class RuntimeTypes {
 
   Set<ClassElement> getClassesUsedInSubstitutions(
       JavaScriptBackend backend, TypeChecks checks);
-  void computeClassesNeedingRti();
+  void computeClassesNeedingRti(
+      ResolutionWorldBuilder resolverWorld, ClosedWorld closedWorld);
 
   /// Compute the required type checkes and substitutions for the given
   /// instantitated and checked classes.
@@ -214,7 +215,8 @@ class _RuntimeTypes implements RuntimeTypes {
   }
 
   @override
-  void computeClassesNeedingRti() {
+  void computeClassesNeedingRti(
+      ResolutionWorldBuilder resolverWorld, ClosedWorld closedWorld) {
     // Find the classes that need runtime type information. Such
     // classes are:
     // (1) used in a is check with type variables,
@@ -227,7 +229,7 @@ class _RuntimeTypes implements RuntimeTypes {
       classesNeedingRti.add(cls);
 
       // TODO(ngeoffray): This should use subclasses, not subtypes.
-      compiler.closedWorld.forEachStrictSubtypeOf(cls, (ClassElement sub) {
+      closedWorld.forEachStrictSubtypeOf(cls, (ClassElement sub) {
         potentiallyAddForRti(sub);
       });
 
@@ -240,7 +242,7 @@ class _RuntimeTypes implements RuntimeTypes {
     }
 
     Set<ClassElement> classesUsingTypeVariableTests = new Set<ClassElement>();
-    compiler.resolverWorld.isChecks.forEach((DartType type) {
+    resolverWorld.isChecks.forEach((DartType type) {
       if (type.isTypeVariable) {
         TypeVariableElement variable = type.element;
         // GENERIC_METHODS: When generic method support is complete enough to