Use MockSdk to speed-up tests.

pkg/analyzer2dart/bin/analyzer2dart.dart

 // Copyright (c) 2014, 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.
 
 /** The entry point for the command-line version analyzer2dart. */
 library analyzer2dart.cmdline;
 
 import 'package:analyzer/analyzer.dart';
 import 'package:analyzer/src/generated/element.dart';
+import 'package:analyzer/src/generated/sdk.dart';
+import 'package:analyzer/src/generated/sdk_io.dart';
 import 'package:analyzer/src/generated/source_io.dart';
 
 import '../lib/src/closed_world.dart';
 import '../lib/src/driver.dart';
 
 void main(List<String> args) {
   // TODO(paulberry): hacky
   String path = args[0];
 
-  Driver analyzer2Dart = new Driver();
+  DartSdk sdk = DirectoryBasedDartSdk.defaultSdk;
+  Driver analyzer2Dart = new Driver(sdk);
 
   // Tell the analysis server about the root
   Source source = analyzer2Dart.setRealRoot(path);
 
   // Get the library element associated with the source.
   FunctionElement entryPointElement = analyzer2Dart.resolveEntryPoint(source);
 
   // TODO(brianwilkerson,paulberry,johnniwinther): Perform tree-growing by
   // visiting the ast and feeding the dependencies into a work queue (enqueuer).
   ClosedWorld world = analyzer2Dart.computeWorld(entryPointElement);
 
   // TODO(brianwilkerson,paulberry,johnniwinther): Convert the ast into cps by
   // visiting the ast and invoking the ir builder.
   new CpsGeneratingVisitor();
 
   // TODO(johnniwinther): Convert the analyzer element model into the dart2js
   // element model to fit the needs of the cps encoding above.
 
   // TODO(johnniwinther): Feed the cps ir into the new dart2dart backend to
   // generate dart file(s).
 }
 
 class CpsGeneratingVisitor extends RecursiveAstVisitor {
   // TODO(johnniwinther)
 }