Adapt TypeMask tests to new TypeMask interface.

tests/compiler/dart2js/union_type_test.dart

Index: tests/compiler/dart2js/union_type_test.dart
diff --git a/tests/compiler/dart2js/union_type_test.dart b/tests/compiler/dart2js/union_type_test.dart
index ae59da3c263f6c2bb7cc5e8614fab45f75e24421..5cbecc1e27e2e03c455869ebb2338422f0438d5f 100644
--- a/tests/compiler/dart2js/union_type_test.dart
+++ b/tests/compiler/dart2js/union_type_test.dart
@@ -11,10 +11,12 @@ import "package:compiler/implementation/types/types.dart";
 import "package:compiler/implementation/dart_types.dart";
 
 main() {
-  asyncTest(() => MockCompiler.create((MockCompiler compiler) {
-    compiler.intClass.ensureResolved(compiler);
-    compiler.stringClass.ensureResolved(compiler);
-
+  MockCompiler compiler = new MockCompiler.internal(analyzeOnly: true);

[karlklose, 2014/09/09 10:59:15]

Why this change?

[herhut, 2014/09/09 11:03:58]

A call to [create] only creates a compiler but does not run anything. Just
manually resolving classes, however, is no longer good enough, as TypeMasks only
deal in live classes. So we need to actually run resolution, which the call to
runCompiler facilitates.

+  asyncTest(() => compiler.runCompiler(null, """
+      main() {
+        print(2); print("Hello");
+      }
+    """).then((_) {
     FlatTypeMask mask1 =
         new FlatTypeMask.exact(compiler.intClass);
     FlatTypeMask mask2 =