Bring back initPolymer, allow boot.js only if using "polymer_experimental.html".

pkg/polymer/e2e_test/canonicalization/test/dir/deploy2_test.dart

Index: pkg/polymer/e2e_test/canonicalization/test/dir/deploy2_test.dart
diff --git a/pkg/polymer/example/canonicalization/test/dir/dir2_test.dart b/pkg/polymer/e2e_test/canonicalization/test/dir/deploy2_test.dart
similarity index 66%
rename from pkg/polymer/example/canonicalization/test/dir/dir2_test.dart
rename to pkg/polymer/e2e_test/canonicalization/test/dir/deploy2_test.dart
index d4c55dca31f6639252960b0036ba793c80e1ad70..e2f632e6b1db29a24106e7dc0ea2f3403f2f1b74 100644
--- a/pkg/polymer/example/canonicalization/test/dir/dir2_test.dart
+++ b/pkg/polymer/e2e_test/canonicalization/test/dir/deploy2_test.dart
@@ -3,9 +3,5 @@
 // BSD-style license that can be found in the LICENSE file.
 
 /// Tests canonicalization at deployment time from a subdir.
-library canonicalization.test.dir2_test;
-
-import 'package:polymer/polymer.dart';
-import '../common.dart';
-
-@initMethod main() => tests();
+library canonicalization.test.dir.deploy2_test;
+export 'deploy_common.dart';