Move URLLoaderClientImpl to a separate file

content/test/BUILD.gn

 # 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.
 
 import("//build/config/chrome_build.gni")
 import("//build/config/compiler/compiler.gni")
 import("//build/config/crypto.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//media/media_options.gni")
@@ skipping 1258 matching lines @@
     "../child/indexed_db/mock_webidbcallbacks.h",
     "../child/indexed_db/webidbcursor_impl_unittest.cc",
     "../child/indexed_db/webidbdatabase_impl_unittest.cc",
     "../child/memory/child_memory_coordinator_impl_unittest.cc",
     "../child/notifications/notification_data_conversions_unittest.cc",
     "../child/resource_dispatcher_unittest.cc",
     "../child/service_worker/service_worker_dispatcher_unittest.cc",
     "../child/shared_memory_data_consumer_handle_unittest.cc",
     "../child/shared_memory_received_data_factory_unittest.cc",
     "../child/site_isolation_stats_gatherer_unittest.cc",
+    "../child/test_request_peer.cc",
+    "../child/test_request_peer.h",
+    "../child/url_loader_client_impl_unittest.cc",
     "../child/url_response_body_consumer_unittest.cc",
     "../child/v8_value_converter_impl_unittest.cc",
     "../child/web_data_consumer_handle_impl_unittest.cc",
     "../child/web_url_loader_impl_unittest.cc",
     "../child/worker_thread_registry_unittest.cc",
     "../common/android/address_parser_unittest.cc",
     "../common/android/gin_java_bridge_value_unittest.cc",
     "../common/bluetooth/web_bluetooth_device_id_unittest.cc",
     "../common/common_param_traits_unittest.cc",
     "../common/cross_site_document_classifier_unittest.cc",
@@ skipping 444 matching lines @@
   if (is_android) {
     deps += [ "//testing/android/native_test:native_test_native_code" ]
   }
 }
 
 group("fuzzers") {
   deps = [
     "//content/test/fuzzer",
   ]
 }