Fix crash on extension IME reloading on Linux Desktop with chromeos=1.

chrome/browser/chromeos/input_method/input_method_engine_ibus.cc

 // 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.
 
 #include "chrome/browser/chromeos/input_method/input_method_engine_ibus.h"
 
 #define XK_MISCELLANY
 #include <X11/keysymdef.h>
 #include <map>
 
@@ skipping 43 matching lines @@
       observer_(NULL),
       preedit_text_(new IBusText()),
       preedit_cursor_(0),
       component_(new IBusComponent()),
       table_(new IBusLookupTable()),
       window_visible_(false),
       weak_ptr_factory_(this) {
 }
 
 InputMethodEngineIBus::~InputMethodEngineIBus() {
-  if (object_path_.IsValid())
-    GetCurrentService()->UnsetEngine();
   input_method::GetInputMethodManager()->RemoveInputMethodExtension(ibus_id_);
+
+  // Do not unset engine before removing input method extension, above function
+  // may call reset function of engine object.
+  // TODO(nona): Call Reset manually here and remove relevant code from
+  //             InputMethodManager once ibus-daemon is gone. (crbug.com/158273)
+  GetCurrentService()->UnsetEngine(this);
 }
 
 void InputMethodEngineIBus::Initialize(
     InputMethodEngine::Observer* observer,
     const char* engine_name,
     const char* extension_id,
     const char* engine_id,
     const char* description,
     const char* language,
     const std::vector<std::string>& layouts,
@@ skipping 539 matching lines @@
   DBusThreadManager::Get()->RemoveIBusEngineService(object_path_);
 
   current_object_path_++;
   object_path_ = dbus::ObjectPath(kObjectPathPrefix +
                                   base::IntToString(current_object_path_));
   GetCurrentService()->SetEngine(this);
   sender.Run(object_path_);
 }
 
 }  // namespace chromeos