Update unit tests

dart/pkg/compiler/lib/src/use_unused_api.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /// This file use methods that aren't used by dart2js.dart, but that we wish to
 /// keep anyway. This might be general API that isn't currently in use,
 /// debugging aids, or API only used for testing (see TODO below).
 
 library dart2js.use_unused_api;
 
@@ skipping 45 matching lines @@
   useColor();
   useFilenames();
   useSsa(null);
   useCodeBuffer(null);
   usedByTests();
   useElements(null, null, null, null, null);
   useIr(null, null, null);
   useCompiler(null);
   useTypes();
   useCodeEmitterTask(null);
+  useScript(null);
 }
 
 useApi() {
   api.ReadStringFromUri uri;
 }
 
 void useConstant(constants.ConstantValue constant,
                  dart2jslib.ConstantSystem cs) {
   constant.isObject;
   cs.isBool(constant);
@@ skipping 187 matching lines @@
   compiler.forgetElement(null);
 }
 
 useTypes() {
   new dart_types.ResolvedTypedefType(null, null, null).unalias(null);
 }
 
 useCodeEmitterTask(js_emitter.CodeEmitterTask codeEmitterTask) {
   codeEmitterTask.oldEmitter.clearCspPrecompiledNodes();
 }
+
+useScript(dart2jslib.Script script) {
+  script.copyWithFile(null);
+}