Introduce WebRequestResourceType.

extensions/browser/api/web_request/BUILD.gn

 # 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.
 
 source_set("web_request") {
   sources = [
     "form_data_parser.cc",
     "form_data_parser.h",
     "upload_data_presenter.cc",
     "upload_data_presenter.h",
     "web_request_api.cc",
     "web_request_api.h",
     "web_request_api_constants.cc",
     "web_request_api_constants.h",
     "web_request_api_helpers.cc",
     "web_request_api_helpers.h",
     "web_request_event_details.cc",
     "web_request_event_details.h",
     "web_request_event_router_delegate.h",
     "web_request_permissions.cc",
     "web_request_permissions.h",
+    "web_request_resource_type.cc",
+    "web_request_resource_type.h",
     "web_request_time_tracker.cc",
     "web_request_time_tracker.h",
   ]
 
   configs += [
     # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
     "//build/config/compiler:no_size_t_to_int_warning",
   ]
 
   deps = [
     "//components/web_cache/browser",
     "//content/public/browser",
     "//content/public/common",
     "//extensions/common/api",
     "//extensions/strings",
     "//third_party/re2",
   ]
 }