[Chromoting] Use device::PowerSaveBlocker to block screen saver

remoting/host/remoting_me2me_host.cc

Index: remoting/host/remoting_me2me_host.cc
diff --git a/remoting/host/remoting_me2me_host.cc b/remoting/host/remoting_me2me_host.cc
index dd5e5fc8af3822341a54e20f43afcc882367729c..e8c7a9bef66ec110ccb6acb80ff06321c8aa0f99 100644
--- a/remoting/host/remoting_me2me_host.cc
+++ b/remoting/host/remoting_me2me_host.cc
@@ -1453,8 +1453,7 @@ void HostProcess::StartHost() {
 
   host_.reset(new ChromotingHost(desktop_environment_factory_.get(),
                                  std::move(session_manager), transport_context,
-                                 context_->audio_task_runner(),
-                                 context_->video_encode_task_runner()));
+                                 *context_));
 
   if (gnubby_auth_policy_enabled_ && gnubby_extension_supported_) {
     host_->AddExtension(base::WrapUnique(new GnubbyExtension()));