mash: Migrate ScopedTargetRootWindow to //ash/common

ash/mus/bridge/wm_shell_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/bridge/wm_shell_mus.h"
 
 #include <utility>
 
 #include "ash/common/accelerators/accelerator_controller.h"
 #include "ash/common/display/display_info.h"
 #include "ash/common/keyboard/keyboard_ui.h"
+#include "ash/common/scoped_root_window_for_new_windows.h"
 #include "ash/common/session/session_state_delegate.h"
 #include "ash/common/shell_delegate.h"
 #include "ash/common/shell_observer.h"
 #include "ash/common/shell_window_ids.h"
 #include "ash/common/system/tray/default_system_tray_delegate.h"
 #include "ash/common/wm/maximize_mode/maximize_mode_event_handler.h"
 #include "ash/common/wm/maximize_mode/scoped_disable_internal_mouse_and_keyboard.h"
 #include "ash/common/wm/mru_window_tracker.h"
 #include "ash/common/wm/window_cycle_event_filter.h"
 #include "ash/common/wm/window_resizer.h"
@@ skipping 182 matching lines @@
 
 WmWindow* WmShellMus::GetRootWindowForDisplayId(int64_t display_id) {
   return GetRootWindowControllerWithDisplayId(display_id)->GetWindow();
 }
 
 WmWindow* WmShellMus::GetRootWindowForNewWindows() {
   NOTIMPLEMENTED();
   return root_window_controllers_[0]->GetWindow();
 }
 
+std::unique_ptr<ScopedRootWindowForNewWindows>
+WmShellMus::CreateScopedRootWindowForNewWindows(WmWindow* root) {
+  NOTIMPLEMENTED();
+  return nullptr;
+}
+
 const DisplayInfo& WmShellMus::GetDisplayInfo(int64_t display_id) const {
   NOTIMPLEMENTED();
   static DisplayInfo fake_info;
   return fake_info;
 }
 
 bool WmShellMus::IsActiveDisplayId(int64_t display_id) const {
   // TODO: implement http://crbug.com/622480.
   NOTIMPLEMENTED();
   return true;
@@ skipping 142 matching lines @@
                     OnWindowActivated(gained_active, lost_active));
 }
 
 void WmShellMus::OnDidDestroyClient(ui::WindowTreeClient* client) {
   DCHECK_EQ(window_tree_client(), client);
   client->RemoveObserver(this);
 }
 
 }  // namespace mus
 }  // namespace ash