Connect to DesktopEnvironment's stubs only when audio/video schedulers are about to be created.

remoting/host/client_session.h

Index: remoting/host/client_session.h
diff --git a/remoting/host/client_session.h b/remoting/host/client_session.h
index c4e06570f352bd5d4e2d82cf5909c523a24003fc..850b5468bde81ae0a5c077f4f366269cbe13d764 100644
--- a/remoting/host/client_session.h
+++ b/remoting/host/client_session.h
@@ -133,10 +133,6 @@ class ClientSession
     return connection_.get();
   }
 
-  DesktopEnvironment* desktop_environment() const {
-    return desktop_environment_.get();
-  }
-
   const std::string& client_jid() { return client_jid_; }
 
   bool is_authenticated() { return auth_input_filter_.enabled();  }
@@ -181,13 +177,8 @@ class ClientSession
 
   std::string client_jid_;
 
-  // The host clipboard and input stubs to which this object delegates.
-  // These are the final elements in the clipboard & input pipelines, which
-  // appear in order below.
-  protocol::ClipboardStub* host_clipboard_stub_;
-  protocol::InputStub* host_input_stub_;
-
-  // Tracker used to release pressed keys and buttons when disconnecting.
+  // Tracker used to release pressed keys and buttons when disconnecting. It is
+  // the final element in the input pipeline.
   protocol::InputEventTracker input_tracker_;
 
   // Filter used to disable remote inputs during local input activity.
@@ -197,7 +188,8 @@ class ClientSession
   MouseClampingFilter mouse_clamping_filter_;
 
   // Filter to used to stop clipboard items sent from the client being echoed
-  // back to it.
+  // back to it.  It is the final element in the clipboard (client -> host)
+  // pipeline.
   protocol::ClipboardEchoFilter clipboard_echo_filter_;
 
   // Filters used to manage enabling & disabling of input & clipboard.