Remove Compiler.mainApp and Compiler.mainFunction

tests/compiler/dart2js/instantiated_classes_test.dart

Index: tests/compiler/dart2js/instantiated_classes_test.dart
diff --git a/tests/compiler/dart2js/instantiated_classes_test.dart b/tests/compiler/dart2js/instantiated_classes_test.dart
index b270135bad8ddf95f8f3e89390038e7eaf350c11..a55da9060d39e1a09c0f6a400900d8161c5ccae5 100644
--- a/tests/compiler/dart2js/instantiated_classes_test.dart
+++ b/tests/compiler/dart2js/instantiated_classes_test.dart
@@ -7,7 +7,8 @@ library instantiated_classes_test;
 import 'dart:async';
 import 'package:expect/expect.dart';
 import 'package:async_helper/async_helper.dart';
-import 'package:compiler/src/elements/entities.dart' show ClassEntity;
+import 'package:compiler/src/elements/entities.dart'
+    show ClassEntity, LibraryEntity;
 import 'type_test_helper.dart';
 
 void main() {
@@ -90,11 +91,13 @@ Future test(String source, List<String> directlyInstantiatedClasses,
   return TypeEnvironment
       .create(source, mainSource: mainSource.toString(), useMockCompiler: true)
       .then((env) {
+    LibraryEntity mainLibrary =
+        env.compiler.frontendStrategy.elementEnvironment.mainLibrary;
     Iterable<ClassEntity> expectedClasses =
         directlyInstantiatedClasses.map(env.getElement);
     Iterable<ClassEntity> actualClasses = env
         .compiler.resolutionWorldBuilder.directlyInstantiatedClasses
-        .where((c) => c.library == env.compiler.mainApp);
+        .where((c) => c.library == mainLibrary);
     Expect.setEquals(expectedClasses, actualClasses);
   });
 }