All strong mode cleaning of dart2js.

tests/compiler/dart2js/type_mask_test.dart

Index: tests/compiler/dart2js/type_mask_test.dart
diff --git a/tests/compiler/dart2js/type_mask_test.dart b/tests/compiler/dart2js/type_mask_test.dart
index 2209aad0a167d2a8e2864b6ce37b12a5532b3d19..7da68ac7c0b0bfa82b9a8667b6de005b1953d6e2 100644
--- a/tests/compiler/dart2js/type_mask_test.dart
+++ b/tests/compiler/dart2js/type_mask_test.dart
@@ -23,10 +23,10 @@ main() {
   var compiler = compilerFor(CODE, uri);
   asyncTest(() => compiler.run(uri).then((_) {
         var closedWorld = compiler.resolutionWorldBuilder.closedWorldForTesting;
-        var classA = findElement(compiler, 'A');
-        var classB = findElement(compiler, 'B');
-        var classC = findElement(compiler, 'C');
-        var classD = findElement(compiler, 'D');
+        dynamic classA = findElement(compiler, 'A');
+        dynamic classB = findElement(compiler, 'B');
+        dynamic classC = findElement(compiler, 'C');
+        dynamic classD = findElement(compiler, 'D');
 
         var exactA = new TypeMask.nonNullExact(classA, closedWorld);
         var exactB = new TypeMask.nonNullExact(classB, closedWorld);