Refactor enqueuers

tests/compiler/dart2js/type_combination_test.dart

Index: tests/compiler/dart2js/type_combination_test.dart
diff --git a/tests/compiler/dart2js/type_combination_test.dart b/tests/compiler/dart2js/type_combination_test.dart
index f15d471f1ad76899cb623db3812f7004967cf294..5ca7197b47512d44ebed9051fe190e3e7c75aa4f 100644
--- a/tests/compiler/dart2js/type_combination_test.dart
+++ b/tests/compiler/dart2js/type_combination_test.dart
@@ -740,19 +740,18 @@ void main() {
     helpers.interceptorsLibrary.forEachLocalMember((element) {
       if (element.isClass) {
         element.ensureResolved(compiler.resolution);
-        backend.registerInstantiatedType(element.rawType,
-            compiler.enqueuer.resolution, compiler.globalDependencies);
+        compiler.enqueuer.resolution.registerInstantiatedType(element.rawType);
       }
     });
     ClassElement patternImplClass = compiler.mainApp.find('PatternImpl');
     patternImplClass.ensureResolved(compiler.resolution);
 
-    backend.registerInstantiatedType(compiler.coreTypes.mapType(),
-        compiler.enqueuer.resolution, compiler.globalDependencies);
-    backend.registerInstantiatedType(compiler.coreTypes.functionType,
-        compiler.enqueuer.resolution, compiler.globalDependencies);
-    backend.registerInstantiatedType(patternImplClass.rawType,
-        compiler.enqueuer.resolution, compiler.globalDependencies);
+    compiler.enqueuer.resolution
+        .registerInstantiatedType(compiler.coreTypes.mapType());
+    compiler.enqueuer.resolution
+        .registerInstantiatedType(compiler.coreTypes.functionType);
+    compiler.enqueuer.resolution
+        .registerInstantiatedType(patternImplClass.rawType);
     compiler.openWorld.closeWorld();
 
     // Grab hold of a supertype for String so we can produce potential