Enable Config::MUS to use classic IME instead of servicified IME.

ash/shell.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 "ash/shell.h"
 
 #include <algorithm>
 #include <string>
 #include <utility>
 
@@ skipping 917 matching lines @@
   }
 
   if (cursor_manager_) {
     cursor_manager_->SetDisplay(
         display::Screen::GetScreen()->GetPrimaryDisplay());
   }
 
   accelerator_controller_ = shell_port_->CreateAcceleratorController();
   maximize_mode_controller_ = base::MakeUnique<MaximizeModeController>();
 
-  if (config == Config::CLASSIC) {
-    // Not applicable to mus/mash as events are already routed to InputMethod
-    // first.
+  if (config == Config::CLASSIC || config == Config::MUS) {
+    // Not applicable to mash as events are already routed to InputMethod first.
     AddPreTargetHandler(
         window_tree_host_manager_->input_method_event_handler());
   }
 
   magnifier_key_scroll_handler_ = MagnifierKeyScroller::CreateHandler();
   AddPreTargetHandler(magnifier_key_scroll_handler_.get());
   speech_feedback_handler_ = SpokenFeedbackToggler::CreateHandler();
   AddPreTargetHandler(speech_feedback_handler_.get());
 
   // The order in which event filters are added is significant.
@@ skipping 291 matching lines @@
 void Shell::OnPrefServiceInitialized(
     std::unique_ptr<::PrefService> pref_service) {
   if (!instance_)
     return;
   // |pref_service_| is null if can't connect to Chrome (as happens when
   // running mash outside of chrome --mash and chrome isn't built).
   pref_service_ = std::move(pref_service);
 }
 
 }  // namespace ash