[Media Router] Factor extension-related logic out of MediaRouterMojoImpl

chrome/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("//chrome/common/features.gni")
@@ skipping 3730 matching lines @@
       "../browser/lifetime/keep_alive_registry_unittest.cc",
       "../browser/media/router/discovery/dial/device_description_fetcher_unittest.cc",
       "../browser/media/router/discovery/dial/device_description_service_unittest.cc",
       "../browser/media/router/discovery/dial/dial_device_data_unittest.cc",
       "../browser/media/router/discovery/dial/dial_media_sink_service_impl_unittest.cc",
       "../browser/media/router/discovery/dial/dial_media_sink_service_proxy_unittest.cc",
       "../browser/media/router/discovery/dial/dial_registry_unittest.cc",
       "../browser/media/router/discovery/dial/dial_service_unittest.cc",
       "../browser/media/router/discovery/mdns/dns_sd_registry_unittest.cc",
       "../browser/media/router/discovery/media_sink_service_base_unittest.cc",
+      "../browser/media/router/event_page_request_manager_unittest.cc",
 
       # TODO(crbug.com/646627):
       # Move media_router_ui_service_factory_unittest.cc to chrome/browser/ui.
       "../browser/media/router/media_router_ui_service_factory_unittest.cc",
       "../browser/media/router/mojo/media_route_controller_unittest.cc",
       "../browser/media/router/mojo/media_router_mojo_impl_unittest.cc",
       "../browser/media/router/mojo/media_router_mojo_metrics_unittest.cc",
       "../browser/policy/local_sync_policy_handler_unittest.cc",
       "../browser/renderer_context_menu/render_view_context_menu_test_util.cc",
       "../browser/renderer_context_menu/render_view_context_menu_test_util.h",
@@ skipping 1417 matching lines @@
 }
 
 if (is_win) {
   loadable_module("conflicts_dll") {
     testonly = true
     sources = [
       "conflicts/conflicts_dll.cc",
     ]
   }
 }