[Media Router] (device discovery) Create MediaSinkService interface

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("//mojo/public/tools/bindings/mojom.gni")
 import("//testing/test.gni")
 
 static_library("router") {
   deps = [
@@ skipping 23 matching lines @@
     "media_router_dialog_controller.cc",
     "media_router_dialog_controller.h",
     "media_router_factory.cc",
     "media_router_factory.h",
     "media_router_metrics.cc",
     "media_router_metrics.h",
     "media_routes_observer.cc",
     "media_routes_observer.h",
     "media_sink.cc",
     "media_sink.h",
+    "media_sink_service.h",
     "media_sinks_observer.cc",
     "media_sinks_observer.h",
     "media_source.cc",
     "media_source.h",
     "media_source_helper.cc",
     "media_source_helper.h",
     "offscreen_presentation_manager.cc",
     "offscreen_presentation_manager.h",
     "offscreen_presentation_manager_factory.cc",
     "offscreen_presentation_manager_factory.h",
@@ skipping 71 matching lines @@
     deps += [
       ":mojo_bindings",
       "//extensions/common",
     ]
     sources += [
       "mojo/media_router_mojo_test.cc",
       "mojo/media_router_mojo_test.h",
     ]
   }
 }