headless: Fix inconsistent header naming

headless/BUILD.gn

 # Copyright 2015 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.
 
 import("//build/config/chrome_build.gni")
 import("//mojo/public/tools/bindings/mojom.gni")
 import("//testing/test.gni")
 import("//tools/grit/grit_rule.gni")
 import("//tools/grit/repack.gni")
 
@@ skipping 119 matching lines @@
 
   outputs = generated_devtools_api
 
   sources = [
     "lib/browser/devtools_api/deprecated_type_conversions_h.template",
     "lib/browser/devtools_api/deprecated_types_h.template",
     "lib/browser/devtools_api/domain_cc.template",
     "lib/browser/devtools_api/domain_h.template",
     "lib/browser/devtools_api/domain_type_conversions_h.template",
     "lib/browser/devtools_api/domain_types_cc.template",
-    "lib/browser/devtools_api/domain_types_forward_declaration_h.template",
+    "lib/browser/devtools_api/domain_types_forward_declarations_h.template",
     "lib/browser/devtools_api/domain_types_h.template",
   ]
 
   args = [
     "--protocol",
     rebase_path(inputs[0], root_build_dir),
     "--output_dir",
     rebase_path(target_gen_dir) + "/public",
   ]
 }
@@ skipping 210 matching lines @@
 
 executable("headless_shell") {
   sources = [
     "app/headless_shell_main.cc",
   ]
 
   deps = [
     "//headless:headless_shell_lib",
   ]
 }