Don't crash in ~HostNPScriptObject() when the object wasn't initialized.

remoting/host/chromoting_host_context.cc

 // Copyright (c) 2011 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/host/chromoting_host_context.h"
 
 #include <string>
 
 #include "base/bind.h"
 #include "base/threading/thread.h"
 #include "remoting/jingle_glue/jingle_thread.h"
 
 namespace remoting {
 
 ChromotingHostContext::ChromotingHostContext(
     base::MessageLoopProxy* ui_message_loop)
     : main_thread_("ChromotingMainThread"),
       encode_thread_("ChromotingEncodeThread"),
       desktop_thread_("ChromotingDesktopThread"),
       ui_message_loop_(ui_message_loop) {
 }
 
 ChromotingHostContext::~ChromotingHostContext() {
 }
 
-void ChromotingHostContext::Start() {
+bool ChromotingHostContext::Start() {
   // Start all the threads.
-  main_thread_.Start();
-  encode_thread_.Start();
-  jingle_thread_.Start();
-  desktop_thread_.Start();
-}
-
-void ChromotingHostContext::Stop() {
-  // Stop all the threads.
-  jingle_thread_.Stop();
-  encode_thread_.Stop();
-  main_thread_.Stop();
-  desktop_thread_.Stop();
+  return main_thread_.Start() && encode_thread_.Start() &&
+      jingle_thread_.Start() && desktop_thread_.Start();
 }
 
 JingleThread* ChromotingHostContext::jingle_thread() {
   return &jingle_thread_;
 }
 
 base::MessageLoopProxy* ChromotingHostContext::ui_message_loop() {
   return ui_message_loop_;
 }
 
 MessageLoop* ChromotingHostContext::main_message_loop() {
   return main_thread_.message_loop();
 }
 
 MessageLoop* ChromotingHostContext::encode_message_loop() {
   return encode_thread_.message_loop();
 }
 
 base::MessageLoopProxy* ChromotingHostContext::network_message_loop() {
   return jingle_thread_.message_loop_proxy();
 }
 
 MessageLoop* ChromotingHostContext::desktop_message_loop() {
   return desktop_thread_.message_loop();
 }
 
 }  // namespace remoting