Remove ArcImeService from window observers on shutdown

components/arc/ime/arc_ime_service.cc

 // Copyright 2016 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 "components/arc/ime/arc_ime_service.h"
 
 #include <utility>
 
 #include "base/logging.h"
 #include "base/strings/utf_string_conversions.h"
@@ skipping 56 matching lines @@
   aura::Env* env = aura::Env::GetInstanceDontCreate();
   if (env)
     env->AddObserver(this);
 }
 
 ArcImeService::~ArcImeService() {
   ui::InputMethod* const input_method = GetInputMethod();
   if (input_method)
     input_method->DetachTextInputClient(this);
 
+  if (focused_arc_window_)
+    focused_arc_window_->RemoveObserver(this);
   if (is_focus_observer_installed_)
     arc_window_delegate_->UnregisterFocusObserver();
   aura::Env* env = aura::Env::GetInstanceDontCreate();
   if (env)
     env->RemoveObserver(this);
   // Removing |this| from KeyboardController.
   keyboard::KeyboardController* keyboard_controller =
       keyboard::KeyboardController::GetInstance();
   if (keyboard_controller && keyboard_controller_ == keyboard_controller) {
     keyboard_controller_->RemoveObserver(this);
@@ skipping 306 matching lines @@
     base::i18n::TextDirection direction) {
   return false;
 }
 
 bool ArcImeService::IsTextEditCommandEnabled(
     ui::TextEditCommand command) const {
   return false;
 }
 
 }  // namespace arc