dart2js: Trust type annotations more often with --trust-type-annotation.

tests/compiler/dart2js/trust_type_annotations2_test.dart

Index: tests/compiler/dart2js/trust_type_annotations2_test.dart
diff --git a/tests/compiler/dart2js/use_checks_test.dart b/tests/compiler/dart2js/trust_type_annotations2_test.dart
similarity index 77%
copy from tests/compiler/dart2js/use_checks_test.dart
copy to tests/compiler/dart2js/trust_type_annotations2_test.dart
index 67efbd00329c467874a8fdaf32d15ed88da67d22..0ff5a9168356614fd776eddacaefbe959dc7823c 100644
--- a/tests/compiler/dart2js/use_checks_test.dart
+++ b/tests/compiler/dart2js/trust_type_annotations2_test.dart
@@ -8,14 +8,15 @@ import 'memory_compiler.dart';
 
 const MEMORY_SOURCE_FILES = const {
   'main.dart': '''
+
+foo(int x, int y) {
+  return x + y;
+}
+
 main (x, y) {
   if (x != null) {
     if (y != null) {
-      // Forces x and y to be int-checked.
-      int a = x;
-      int b = y;
-      // Now we must be able to do a direct "+" operation in JS.
-      return x + y;
+      return foo(x, y);
     }
   }
 }
@@ -24,7 +25,7 @@ main (x, y) {
 
 main() {
   var compiler = compilerFor(MEMORY_SOURCE_FILES,
-                             options: ['--enable-checked-mode']);
+                             options: ['--trust-type-annotations']);
   asyncTest(() => compiler.runCompiler(Uri.parse('memory:main.dart')).then((_) {
     var element = compiler.mainApp.findExported('main');
     var code = compiler.backend.assembleCode(element);