Allow MediaSession in iframes to be routed

content/browser/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/features.gni")
 import("//build/config/ui.gni")
 import("//media/media_options.gni")
 import("//ppapi/features/features.gni")
 import("//printing/features/features.gni")
 import("//third_party/WebKit/public/public_features.gni")
@@ skipping 882 matching lines @@
     "media/session/media_session_android.h",
     "media/session/media_session_controller.cc",
     "media/session/media_session_controller.h",
     "media/session/media_session_controllers_manager.cc",
     "media/session/media_session_controllers_manager.h",
     "media/session/media_session_impl.cc",
     "media/session/media_session_impl.h",
     "media/session/media_session_player_observer.h",
     "media/session/media_session_service_impl.cc",
     "media/session/media_session_service_impl.h",
+    "media/session/media_session_service_router.cc",
+    "media/session/media_session_service_router.h",
     "media/session/media_session_uma_helper.cc",
     "media/session/media_session_uma_helper.h",
     "media/url_provision_fetcher.cc",
     "media/url_provision_fetcher.h",
     "memory/memory_coordinator.cc",
     "memory/memory_coordinator.h",
     "memory/memory_coordinator_impl.cc",
     "memory/memory_coordinator_impl.h",
     "memory/memory_message_filter.cc",
     "memory/memory_message_filter.h",
@@ skipping 1066 matching lines @@
   if (!is_component_build) {
     public_deps = [
       ":browser",
     ]
   } else {
     public_deps = [
       "//third_party/leveldatabase",
     ]
   }
 }