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

ui/aura/mus/window_tree_host_mus.cc

 // Copyright 2015 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 "ui/aura/mus/window_tree_host_mus.h"
 
 #include "base/memory/ptr_util.h"
 #include "ui/aura/env.h"
 #include "ui/aura/mus/input_method_mus.h"
 #include "ui/aura/mus/window_port_mus.h"
@@ skipping 66 matching lines @@
   OnAcceleratedWidgetAvailable(accelerated_widget,
                                GetDisplay().device_scale_factor());
 
   delegate_->OnWindowTreeHostCreated(this);
 
   // Do not advertise accelerated widget; already set manually.
   const bool use_default_accelerated_widget = false;
   SetPlatformWindow(base::MakeUnique<ui::StubWindow>(
       this, use_default_accelerated_widget, bounds_in_pixels));
 
-  input_method_ = base::MakeUnique<InputMethodMus>(this, window());
-  input_method_->Init(init_params.window_tree_client->connector());
-  SetSharedInputMethod(input_method_.get());
+  if (!init_params.use_classic_ime) {
+    input_method_ = base::MakeUnique<InputMethodMus>(this, window());
+    input_method_->Init(init_params.window_tree_client->connector());
+    SetSharedInputMethod(input_method_.get());
+  }
 
   compositor()->SetHostHasTransparentBackground(true);
 
   // Mus windows are assumed hidden.
   compositor()->SetVisible(false);
 
   if (init_params.frame_sink_id.is_valid())
     window_mus->SetFrameSinkIdFromServer(init_params.frame_sink_id);
 }
 
@@ skipping 112 matching lines @@
 void WindowTreeHostMus::MoveCursorToScreenLocationInPixels(
     const gfx::Point& location_in_pixels) {
   // TODO: this needs to message the server http://crbug.com/693340. Setting
   // the location is really only appropriate in tests, outside of tests this
   // value is ignored.
   NOTIMPLEMENTED();
   Env::GetInstance()->set_last_mouse_location(location_in_pixels);
 }
 
 }  // namespace aura