Added 'dynamic' keyword, so that 'Dynamic' can be deprecated.

tests/compiler/dart2js/compiler_helper.dart

Index: tests/compiler/dart2js/compiler_helper.dart
diff --git a/tests/compiler/dart2js/compiler_helper.dart b/tests/compiler/dart2js/compiler_helper.dart
index 828d84f1ebf169a1b0d6ded6954c5df08e20df2a..6bc228c40269d5ef0701ade28a2126994367d015 100644
--- a/tests/compiler/dart2js/compiler_helper.dart
+++ b/tests/compiler/dart2js/compiler_helper.dart
@@ -47,7 +47,7 @@ String compileAll(String code) {
   return compiler.assembledCode;
 }
 
-Dynamic compileAndCheck(String code,
+dynamic compileAndCheck(String code,
                         String name,
                         check(MockCompiler compiler, lego.Element element)) {
   Uri uri = new Uri.fromComponents(scheme: 'source');