Future proof against things like http://crbug.com/91521

remoting/client/client_context.cc

 // Copyright (c) 2010 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.
 
 #include "remoting/client/client_context.h"
 
 #include <string>
 
 #include "base/threading/thread.h"
+#include "remoting/client/plugin/pepper_util.h"
 #include "remoting/jingle_glue/jingle_thread.h"
 
 namespace remoting {
 
 ClientContext::ClientContext()
     : main_thread_("ChromotingClientMainThread"),
-      decode_thread_("ChromotingClientDecodeThread") {
+      decode_thread_("ChromotingClientDecodeThread"),
+      started_(false) {
 }
 
 ClientContext::~ClientContext() {
 }
 
 void ClientContext::Start() {
   // Start all the threads.
+  DCHECK(CurrentlyOnPluginThread());
   main_thread_.Start();
   decode_thread_.Start();
   jingle_thread_.Start();
+  started_ = true;
 }
 
 void ClientContext::Stop() {
-  // Stop all the threads.
-  jingle_thread_.Stop();
-  decode_thread_.Stop();
-  main_thread_.Stop();
+  DCHECK(CurrentlyOnPluginThread());
+  if (started_) {
+    // Stop all the threads.
+    jingle_thread_.Stop();
+    decode_thread_.Stop();
+    main_thread_.Stop();
+    started_ = false;
+  }
 }
 
 JingleThread* ClientContext::jingle_thread() {
   return &jingle_thread_;
 }
 
 MessageLoop* ClientContext::main_message_loop() {
   return main_thread_.message_loop();
 }
 
 MessageLoop* ClientContext::decode_message_loop() {
   return decode_thread_.message_loop();
 }
 
 MessageLoop* ClientContext::network_message_loop() {
   return jingle_thread_.message_loop();
 }
 
 }  // namespace remoting