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

Source/bindings/templates/dictionary_impl.cpp

Index: Source/bindings/templates/dictionary_impl.cpp
diff --git a/Source/bindings/templates/dictionary_impl.cpp b/Source/bindings/templates/dictionary_impl.cpp
index 80fb9c13fdc1aa2696d8a2c1ab8ae2def101bb0a..2ef799625cf3bb8252f8682ac6587aaab8cbb875 100644
--- a/Source/bindings/templates/dictionary_impl.cpp
+++ b/Source/bindings/templates/dictionary_impl.cpp
@@ -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' %}
 #include "config.h"
 #include "{{cpp_class}}.h"