(Not for review) Dummy C++ side Custom Controls implementation

chrome/browser/media/router/BUILD.gn

Index: chrome/browser/media/router/BUILD.gn
diff --git a/chrome/browser/media/router/BUILD.gn b/chrome/browser/media/router/BUILD.gn
index 5e728ee6b958c0d0b4dcc014ec06ac63b867aa2b..bdc61f24afd1b0fe3279377a2044bf3199aa418f 100644
--- a/chrome/browser/media/router/BUILD.gn
+++ b/chrome/browser/media/router/BUILD.gn
@@ -30,6 +30,7 @@ static_library("router") {
     "issues_observer.h",
     "media_route.cc",
     "media_route.h",
+    "media_route_status_observer.h",
     "media_router.h",
     "media_router_base.cc",
     "media_router_base.h",
@@ -51,6 +52,8 @@ static_library("router") {
     "media_source.h",
     "media_source_helper.cc",
     "media_source_helper.h",
+    "media_status.cc",
+    "media_status.h",
     "offscreen_presentation_manager.cc",
     "offscreen_presentation_manager.h",
     "offscreen_presentation_manager_factory.cc",
@@ -87,6 +90,8 @@ static_library("router") {
       "media_router_ui_service.h",
       "media_router_ui_service_factory.cc",
       "media_router_ui_service_factory.h",
+      "mojo/media_route_controller.cc",
+      "mojo/media_route_controller.h",
       "mojo/media_route_provider_util_win.cc",
       "mojo/media_route_provider_util_win.h",
       "mojo/media_router_mojo_impl.cc",
@@ -99,7 +104,9 @@ static_library("router") {
 
 mojom("mojo_bindings") {
   sources = [
+    "mojo/media_controller.mojom",
     "mojo/media_router.mojom",
+    "mojo/media_status.mojom",
   ]
 
   public_deps = [