Add --use-ime-service command line flag to enable InputMethodMus in --mus.

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>
 
 #include "ash/accelerators/accelerator_controller.h"
 #include "ash/accelerators/accelerator_delegate.h"
 #include "ash/accelerators/ash_focus_manager_factory.h"
 #include "ash/accelerators/magnifier_key_scroller.h"
 #include "ash/accelerators/spoken_feedback_toggler.h"
 #include "ash/accessibility_delegate.h"
 #include "ash/app_list/app_list_delegate_impl.h"
 #include "ash/ash_constants.h"
+#include "ash/ash_switches.h"
 #include "ash/aura/shell_port_classic.h"
 #include "ash/autoclick/autoclick_controller.h"
 #include "ash/cast_config_controller.h"
 #include "ash/devtools/ash_devtools_css_agent.h"
 #include "ash/devtools/ash_devtools_dom_agent.h"
 #include "ash/display/cursor_window_controller.h"
 #include "ash/display/display_color_manager_chromeos.h"
 #include "ash/display/display_configuration_controller.h"
 #include "ash/display/display_error_observer_chromeos.h"
 #include "ash/display/event_transformation_handler.h"
@@ skipping 899 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 || config == Config::MUS) {
+  if (config == Config::CLASSIC ||
+      (config == Config::MUS &&
+       !base::CommandLine::ForCurrentProcess()->HasSwitch(
+           switches::kUseServicifiedIME))) {
     // 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());
 
@@ skipping 294 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