[bindings] Include copyright block in generated code for consistency.

Source/bindings/templates/dictionary_impl.h

Index: Source/bindings/templates/dictionary_impl.h
diff --git a/Source/bindings/templates/dictionary_impl.h b/Source/bindings/templates/dictionary_impl.h
index 029017b634f6a8ba8dfdb1b7626b1c973fd46a67..8544f26126cacd1f9e93a89745afd6b666bc49a3 100644
--- a/Source/bindings/templates/dictionary_impl.h
+++ b/Source/bindings/templates/dictionary_impl.h
@@ -1,9 +1,4 @@
-// Copyright 2014 The Chromium Authors. 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 has been auto-generated by {{code_generator}}. DO NOT MODIFY!
-
+{% include 'copyright_block.txt' %}
 #ifndef {{cpp_class}}_h
 #define {{cpp_class}}_h