Add ClassSet to support ClassWorld.strictSubtypesOf

tests/compiler/dart2js/class_set_test.dart

Index: tests/compiler/dart2js/class_set_test.dart
diff --git a/tests/compiler/dart2js/class_set_test.dart b/tests/compiler/dart2js/class_set_test.dart
index 2e12cdbf7d912491a80101de3412d3b66cd80463..c3ee03117f85a5b686d731328b0767918ea0f913 100644
--- a/tests/compiler/dart2js/class_set_test.dart
+++ b/tests/compiler/dart2js/class_set_test.dart
@@ -55,7 +55,7 @@ void main() {
     void checkClass(ClassElement cls,
                     {bool directlyInstantiated: false,
                      bool indirectlyInstantiated: false}) {
-      ClassHierarchyNode node = world.classHierarchyNode(cls);
+      ClassHierarchyNode node = world.getClassHierarchyNode(cls);
       Expect.isNotNull(node, "Expected ClassHierarchyNode for $cls.");
       Expect.equals(
           directlyInstantiated || indirectlyInstantiated,
@@ -131,7 +131,7 @@ void main() {
     }
 
     iterator = new ClassHierarchyNodeIterable(
-        world.classHierarchyNode(G)).iterator;
+        world.getClassHierarchyNode(G)).iterator;
     checkState(G, currentNode: null, stack: null);
     Expect.isNull(iterator.current);
     Expect.isTrue(iterator.moveNext());
@@ -142,7 +142,8 @@ void main() {
     Expect.isNull(iterator.current);
 
     iterator = new ClassHierarchyNodeIterable(
-        world.classHierarchyNode(G), includeRoot: false).iterator;
+        world.getClassHierarchyNode(G),
+        includeRoot: false).iterator;
     checkState(G, currentNode: null, stack: null);
     Expect.isNull(iterator.current);
     Expect.isFalse(iterator.moveNext());
@@ -150,7 +151,7 @@ void main() {
     Expect.isNull(iterator.current);
 
     iterator = new ClassHierarchyNodeIterable(
-        world.classHierarchyNode(C)).iterator;
+        world.getClassHierarchyNode(C)).iterator;
     checkState(C, currentNode: null, stack: null);
     Expect.isNull(iterator.current);
     Expect.isTrue(iterator.moveNext());
@@ -170,7 +171,7 @@ void main() {
     Expect.isNull(iterator.current);
 
     iterator = new ClassHierarchyNodeIterable(
-        world.classHierarchyNode(D)).iterator;
+        world.getClassHierarchyNode(D)).iterator;
     checkState(D, currentNode: null, stack: null);
     Expect.isNull(iterator.current);
     Expect.isTrue(iterator.moveNext());
@@ -181,7 +182,7 @@ void main() {
     Expect.isNull(iterator.current);
 
     iterator = new ClassHierarchyNodeIterable(
-        world.classHierarchyNode(B)).iterator;
+        world.getClassHierarchyNode(B)).iterator;
     checkState(B, currentNode: null, stack: null);
     Expect.isNull(iterator.current);
     Expect.isTrue(iterator.moveNext());
@@ -195,7 +196,8 @@ void main() {
     Expect.isNull(iterator.current);
 
     iterator = new ClassHierarchyNodeIterable(
-        world.classHierarchyNode(B), includeRoot: false).iterator;
+        world.getClassHierarchyNode(B),
+        includeRoot: false).iterator;
     checkState(B, currentNode: null, stack: null);
     Expect.isNull(iterator.current);
     Expect.isTrue(iterator.moveNext());
@@ -206,7 +208,8 @@ void main() {
     Expect.isNull(iterator.current);
 
     iterator = new ClassHierarchyNodeIterable(
-        world.classHierarchyNode(B), directlyInstantiatedOnly: true).iterator;
+        world.getClassHierarchyNode(B),
+        includeIndirectlyInstantiated: false).iterator;
     checkState(B, currentNode: null, stack: null);
     Expect.isNull(iterator.current);
     Expect.isTrue(iterator.moveNext());
@@ -217,7 +220,7 @@ void main() {
     Expect.isNull(iterator.current);
 
     iterator = new ClassHierarchyNodeIterable(
-        world.classHierarchyNode(A)).iterator;
+        world.getClassHierarchyNode(A)).iterator;
     checkState(A, currentNode: null, stack: null);
     Expect.isNull(iterator.current);
     Expect.isTrue(iterator.moveNext());
@@ -246,7 +249,8 @@ void main() {
     Expect.isNull(iterator.current);
 
     iterator = new ClassHierarchyNodeIterable(
-        world.classHierarchyNode(A), includeRoot: false).iterator;
+        world.getClassHierarchyNode(A),
+        includeRoot: false).iterator;
     checkState(A, currentNode: null, stack: null);
     Expect.isNull(iterator.current);
     Expect.isTrue(iterator.moveNext());
@@ -272,7 +276,8 @@ void main() {
     Expect.isNull(iterator.current);
 
     iterator = new ClassHierarchyNodeIterable(
-        world.classHierarchyNode(A), directlyInstantiatedOnly: true).iterator;
+        world.getClassHierarchyNode(A),
+        includeIndirectlyInstantiated: false).iterator;
     checkState(A, currentNode: null, stack: null);
     Expect.isNull(iterator.current);
     Expect.isTrue(iterator.moveNext());
@@ -298,8 +303,9 @@ void main() {
     Expect.isNull(iterator.current);
 
     iterator = new ClassHierarchyNodeIterable(
-        world.classHierarchyNode(A),
-        includeRoot: false, directlyInstantiatedOnly: true).iterator;
+        world.getClassHierarchyNode(A),
+        includeRoot: false,
+        includeIndirectlyInstantiated: false).iterator;
     checkState(A, currentNode: null, stack: null);
     Expect.isNull(iterator.current);
     Expect.isTrue(iterator.moveNext());