Cleanup headless templates and message_dispatcher.h.

headless/lib/browser/devtools_api/domain_types_forward_declarations_h.template

Index: headless/lib/browser/devtools_api/domain_types_forward_declarations_h.template
diff --git a/headless/lib/browser/devtools_api/domain_types_forward_declarations_h.template b/headless/lib/browser/devtools_api/domain_types_forward_declarations_h.template
index b321a17bc56bd9bee74167cea402842523f8bc04..d1a972c44e6820e2ec76be22190634da881f60a7 100644
--- a/headless/lib/browser/devtools_api/domain_types_forward_declarations_h.template
+++ b/headless/lib/browser/devtools_api/domain_types_forward_declarations_h.template
@@ -1,18 +1,13 @@
 // This file is generated
 
-// Copyright (c) 2016 The Chromium Authors. All rights reserved.
+// Copyright 2016 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.
 
 #ifndef HEADLESS_PUBLIC_DEVTOOLS_INTERNAL_TYPES_FORWARD_DECLARATIONS_{{domain.domain | camelcase_to_hacker_style | upper}}_H_
 #define HEADLESS_PUBLIC_DEVTOOLS_INTERNAL_TYPES_FORWARD_DECLARATIONS_{{domain.domain | camelcase_to_hacker_style | upper}}_H_
 
-#include "base/optional.h"
 #include "base/values.h"
-#include "headless/public/headless_export.h"
-#include "headless/public/util/error_reporter.h"
-
-#include "base/memory/ptr_util.h"
 
 namespace headless {