Remove deprecated Expect from the libraries.

tests/standalone/byte_array_view_optimized_test.dart

 // Copyright (c) 2013, 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.
 
 // Test optimization of byte array views on external data.
 
 // Library tag to be able to run in html test framework.
 library ByteArrayViewOptimizedTest;
 
+import "package:expect/expect.dart";
 import "dart:typeddata";
 
 li16(v) => v[0];
 
 main() {
   var a = new Uint8List.transferable(2);
   a[0] = a[1] = 0xff;
   var b = new Int16List.view(a.buffer);
   Expect.equals(-1, li16(b));
   for (var i=0; i<10000; i++) li16(b);
   Expect.equals(-1, li16(b));
 }