[cast_channel] Make CastSocketService a global leaky singleton

components/cast_channel/BUILD.gn

 # Copyright 2017 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.
 
 static_library("cast_channel") {
   sources = [
     "cast_auth_util.cc",
     "cast_auth_util.h",
     "cast_channel_enum.cc",
     "cast_channel_enum.h",
     "cast_framer.cc",
     "cast_framer.h",
     "cast_message_util.cc",
     "cast_message_util.h",
     "cast_socket.cc",
     "cast_socket.h",
     "cast_socket_service.cc",
     "cast_socket_service.h",
-    "cast_socket_service_factory.cc",
-    "cast_socket_service_factory.h",
     "cast_transport.cc",
     "cast_transport.h",
     "keep_alive_delegate.cc",
     "keep_alive_delegate.h",
     "logger.cc",
     "logger.h",
   ]
   deps = [
     "//base",
     "//components/cast_certificate",
@@ skipping 40 matching lines @@
     "//components/cast_certificate",
     "//components/cast_certificate:test_support",
     "//components/cast_certificate/proto:unittest_proto",
     "//components/cast_channel/proto:cast_channel_proto",
     "//content/test:test_support",
     "//net:test_support",
     "//testing/gmock",
     "//testing/gtest",
   ]
 }