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

chrome/browser/media/router/mojo/media_router_mojo_impl.cc

Index: chrome/browser/media/router/mojo/media_router_mojo_impl.cc
diff --git a/chrome/browser/media/router/mojo/media_router_mojo_impl.cc b/chrome/browser/media/router/mojo/media_router_mojo_impl.cc
index 82bf5d61afcd190d2b1eff7d8f50206112bf1dd8..669e9c29f99b059d4552bec2c6943c2516dcb237 100644
--- a/chrome/browser/media/router/mojo/media_router_mojo_impl.cc
+++ b/chrome/browser/media/router/mojo/media_router_mojo_impl.cc
@@ -21,6 +21,7 @@
 #include "chrome/browser/media/router/media_routes_observer.h"
 #include "chrome/browser/media/router/media_sinks_observer.h"
 #include "chrome/browser/media/router/media_source_helper.h"
+#include "chrome/browser/media/router/mojo/media_route_controller.h"
 #include "chrome/browser/media/router/mojo/media_route_provider_util_win.h"
 #include "chrome/browser/media/router/mojo/media_router_mojo_metrics.h"
 #include "chrome/browser/media/router/route_message.h"
@@ -217,6 +218,8 @@ void MediaRouterMojoImpl::OnRoutesUpdated(
 
   for (auto& observer : it->second->observers)
     observer.OnRoutesUpdated(routes, joinable_route_ids);
+
+  RemoveInvalidMediaRouteControllers(routes);
 }
 
 void MediaRouterMojoImpl::RouteResponseReceived(
@@ -385,6 +388,23 @@ void MediaRouterMojoImpl::SearchSinks(
                         search_input, domain, sink_callback));
 }
 
+MediaRouteController* MediaRouterMojoImpl::GetControllerForRoute(
+    const MediaRoute::Id& route_id) {
+  auto it = route_controllers_.find(route_id);
+  if (it != route_controllers_.end())
+    return it->second.get();
+  route_controllers_[route_id] = base::MakeUnique<MediaRouteController>(
+      route_id, media_route_provider_.get(),
+      base::Bind(&MediaRouterMojoImpl::DestroyMediaRouteController,
+                 base::Unretained(this), route_id));
+  return route_controllers_[route_id].get();
+}
+
+void MediaRouterMojoImpl::DestroyMediaRouteController(
+    const MediaRoute::Id& route_id) {
+  route_controllers_.erase(route_id);
+}
+
 bool MediaRouterMojoImpl::RegisterMediaSinksObserver(
     MediaSinksObserver* observer) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
@@ -935,4 +955,20 @@ void MediaRouterMojoImpl::DoUpdateMediaSinks(
   media_route_provider_->UpdateMediaSinks(source_id);
 }
 
+void MediaRouterMojoImpl::RemoveInvalidMediaRouteControllers(
+    const std::vector<MediaRoute>& routes) {
+  auto it = route_controllers_.begin();
+  while (it != route_controllers_.end()) {
+    const MediaRoute::Id& route_id = it->first;
+    if (std::find_if(routes.begin(), routes.end(),
+                     [&route_id](const MediaRoute& route) {
+                       return route.media_route_id() == route_id;
+                     }) == routes.end()) {
+      it = route_controllers_.erase(it);
+    } else {
+      ++it;
+    }
+  }
+}
+
 }  // namespace media_router