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

chrome/browser/media/router/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("//extensions/features/features.gni")
 import("//testing/test.gni")
 
 static_library("router") {
   deps = [
@@ skipping 53 matching lines @@
     "route_message_observer.h",
   ]
 
   if (enable_extensions) {
     deps += [
       "discovery",
       "//extensions/browser",
       "//mojo/public/cpp/bindings",
     ]
     sources += [
+      "event_page_request_manager.cc",
+      "event_page_request_manager.h",
+      "event_page_request_manager_factory.cc",
+      "event_page_request_manager_factory.h",
+
       # TODO(crbug.com/646627): Move media_router_ui_service* to
       # chrome/browser/ui/.
       "media_router_ui_service.cc",
       "media_router_ui_service.h",
       "media_router_ui_service_factory.cc",
       "media_router_ui_service_factory.h",
       "mojo/media_route_provider_util_win.cc",
       "mojo/media_route_provider_util_win.h",
       "mojo/media_router_mojo_impl.cc",
       "mojo/media_router_mojo_impl.h",
@@ skipping 26 matching lines @@
       "//extensions/common",
     ]
     sources += [
       "discovery/mdns/mock_dns_sd_registry.cc",
       "discovery/mdns/mock_dns_sd_registry.h",
       "mojo/media_router_mojo_test.cc",
       "mojo/media_router_mojo_test.h",
     ]
   }
 }