Check whether the client is connected before trying to write to channels.

remoting/client/plugin/chromoting_instance.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // TODO(ajwong): We need to come up with a better description of the
 // responsibilities for each thread.
 
 #ifndef REMOTING_CLIENT_PLUGIN_CHROMOTING_INSTANCE_H_
 #define REMOTING_CLIENT_PLUGIN_CHROMOTING_INSTANCE_H_
 
@@ skipping 172 matching lines @@
   // Posts trapped keys to the web-app to handle.
   void SendTrappedKey(uint32 usb_keycode, bool pressed);
 
   // Callback for PepperXmppProxy.
   void SendOutgoingIq(const std::string& iq);
 
   void SendPerfStats();
 
   void ProcessLogToUI(const std::string& message);
 
+  // Returns true if there is a ConnectionToHost and it is connected.
+  bool IsConnected();
+
   bool initialized_;
 
   PepperPluginThreadDelegate plugin_thread_delegate_;
   scoped_refptr<PluginMessageLoopProxy> plugin_message_loop_;
   ClientContext context_;
   scoped_ptr<protocol::ConnectionToHost> host_connection_;
   scoped_ptr<PepperView> view_;
 
   scoped_refptr<RectangleUpdateDecoder> rectangle_decoder_;
+
   scoped_ptr<protocol::MouseInputFilter> mouse_input_filter_;
   scoped_ptr<protocol::InputEventTracker> input_tracker_;
   KeyEventMapper key_mapper_;
   scoped_ptr<PepperInputHandler> input_handler_;
   scoped_ptr<ChromotingClient> client_;
 
   // XmppProxy is a refcounted interface used to perform thread-switching and
   // detaching between objects whose lifetimes are controlled by pepper, and
   // jingle_glue objects. This is used when if we start a sandboxed jingle
   // connection.
   scoped_refptr<PepperXmppProxy> xmpp_proxy_;
 
   // JavaScript interface to control this instance.
   // This wraps a ChromotingScriptableObject in a pp::Var.
   pp::Var instance_object_;
 
   scoped_ptr<ScopedThreadProxy> thread_proxy_;
 
   DISALLOW_COPY_AND_ASSIGN(ChromotingInstance);
 };
 
 }  // namespace remoting
 
 #endif  // REMOTING_CLIENT_PLUGIN_CHROMOTING_INSTANCE_H_