Converts mash to use Shell

ash/mus/keyboard_ui_mus.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 "ash/mus/keyboard_ui_mus.h"
 
 #include "ash/common/keyboard/keyboard_ui_observer.h"
 #include "base/memory/ptr_util.h"
 #include "content/public/common/service_names.mojom.h"
 #include "services/service_manager/public/cpp/connector.h"
@@ skipping 11 matching lines @@
 
 KeyboardUIMus::~KeyboardUIMus() {}
 
 // static
 std::unique_ptr<KeyboardUI> KeyboardUIMus::Create(
     service_manager::Connector* connector) {
   return base::MakeUnique<KeyboardUIMus>(connector);
 }
 
 void KeyboardUIMus::Hide() {
-  keyboard_->Hide();
+  if (keyboard_)
+    keyboard_->Hide();
 }
 
 void KeyboardUIMus::Show() {
-  keyboard_->Show();
+  if (keyboard_)
+    keyboard_->Show();
 }
 
 void KeyboardUIMus::ShowInDisplay(const int64_t display_id) {
   // TODO(yhanada): Send display id after adding a display_id argument to
   // |Keyboard::Show()| in keyboard.mojom. See crbug.com/585253.
-  keyboard_->Show();
+  if (keyboard_)
+    keyboard_->Show();
 }
 
 bool KeyboardUIMus::IsEnabled() {
   return is_enabled_;
 }
 
 void KeyboardUIMus::OnKeyboardStateChanged(bool is_enabled,
                                            bool is_visible,
                                            uint64_t display_id,
                                            const gfx::Rect& bounds) {
   if (is_enabled_ == is_enabled)
     return;
 
   is_enabled_ = is_enabled;
   for (auto& observer : *observers())
     observer.OnKeyboardEnabledStateChanged(is_enabled);
 }
 
 }  // namespace ash