Moving host status events monitoring to a separate interface (HostStatusMonitor).

remoting/host/chromoting_host.cc

Index: remoting/host/chromoting_host.cc
diff --git a/remoting/host/chromoting_host.cc b/remoting/host/chromoting_host.cc
index 848b926c7f8c014b48fde844b40ddac48123721b..68009d493aec35b94183ba1eb3aae394aa44fc28 100644
--- a/remoting/host/chromoting_host.cc
+++ b/remoting/host/chromoting_host.cc
@@ -78,7 +78,8 @@ ChromotingHost::ChromotingHost(
       protocol_config_(protocol::CandidateSessionConfig::CreateDefault()),
       login_backoff_(&kDefaultBackoffPolicy),
       authenticating_client_(false),
-      reject_authenticating_client_(false) {
+      reject_authenticating_client_(false),
+      ALLOW_THIS_IN_INITIALIZER_LIST(weak_factory_(this)) {
   DCHECK(signal_strategy);
   DCHECK(network_task_runner_->BelongsToCurrentThread());
 
@@ -409,6 +410,8 @@ void ChromotingHost::ShutdownFinish() {
     it->Run();
   }
   shutdown_tasks_.clear();
+
+  weak_factory_.InvalidateWeakPtrs();
 }
 
 }  // namespace remoting