[MBI]: Use |render_thread_| instead of RenderThread::Get in AgentSchedulingGroup

R=haraken@chromium.org, kouhei@chromium.org, talp@chromium.org

Bug: 1111231
Change-Id: Ia7151587a3459c5262edd5721c63dfec60870cc9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2438709
Commit-Queue: Dominic Farolino <dom@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Tal Pressman <talp@chromium.org>
Reviewed-by: Kouhei Ueno <kouhei@chromium.org>
Cr-Commit-Position: refs/heads/master@{#812463}

content/renderer/agent_scheduling_group.cc

@@ -118,25 +118,19 @@ AgentSchedulingGroup::~AgentSchedulingGroup() = default;
 // IPC messages to be forwarded to the `RenderThread`, for now. In the future
 // they will be handled directly by the `AgentSchedulingGroup`.
 bool AgentSchedulingGroup::Send(IPC::Message* message) {
-  // TODO(crbug.com/1111231): For some reason, changing this to use
-  // render_thread_ causes trybots to time out (not specific tests).
-  return RenderThread::Get()->Send(message);
+  return render_thread_.Send(message);
 }
 
 // IPC messages to be forwarded to the `RenderThread`, for now. In the future
 // they will be handled directly by the `AgentSchedulingGroup`.
 void AgentSchedulingGroup::AddRoute(int32_t routing_id, Listener* listener) {
-  // TODO(crbug.com/1111231): For some reason, changing this to use
-  // render_thread_ causes trybots to time out (not specific tests).
-  RenderThread::Get()->AddRoute(routing_id, listener);
+  render_thread_.AddRoute(routing_id, listener);
 }
 
 // IPC messages to be forwarded to the `RenderThread`, for now. In the future
 // they will be handled directly by the `AgentSchedulingGroup`.
 void AgentSchedulingGroup::RemoveRoute(int32_t routing_id) {
-  // TODO(crbug.com/1111231): For some reason, changing this to use
-  // render_thread_ causes trybots to time out (not specific tests).
-  RenderThread::Get()->RemoveRoute(routing_id);
+  render_thread_.RemoveRoute(routing_id);
 }
 
 mojom::RouteProvider* AgentSchedulingGroup::GetRemoteRouteProvider() {