mash: Migrate ScopedTargetRootWindow to //ash/common

ash/aura/wm_shell_aura.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/aura/wm_shell_aura.h"
 
 #include <utility>
 
 #include "ash/aura/wm_window_aura.h"
 #include "ash/common/session/session_state_delegate.h"
@@ skipping 69 matching lines @@
 WmWindow* WmShellAura::GetPrimaryRootWindow() {
   return WmWindowAura::Get(Shell::GetPrimaryRootWindow());
 }
 
 WmWindow* WmShellAura::GetRootWindowForDisplayId(int64_t display_id) {
   return WmWindowAura::Get(Shell::GetInstance()
                                ->window_tree_host_manager()
                                ->GetRootWindowForDisplayId(display_id));
 }
 
-WmWindow* WmShellAura::GetRootWindowForNewWindows() {
-  return WmWindowAura::Get(Shell::GetTargetRootWindow());
-}
-
 const DisplayInfo& WmShellAura::GetDisplayInfo(int64_t display_id) const {
   return Shell::GetInstance()->display_manager()->GetDisplayInfo(display_id);
 }
 
 bool WmShellAura::IsActiveDisplayId(int64_t display_id) const {
   return Shell::GetInstance()->display_manager()->IsActiveDisplayId(display_id);
 }
 
 bool WmShellAura::IsForceMaximizeOnFirstRun() {
   return delegate()->IsForceMaximizeOnFirstRun();
@@ skipping 119 matching lines @@
   Shell::GetInstance()
       ->virtual_keyboard_controller()
       ->ToggleIgnoreExternalKeyboard();
 }
 #endif
 
 void WmShellAura::OnWindowActivated(
     aura::client::ActivationChangeObserver::ActivationReason reason,
     aura::Window* gained_active,
     aura::Window* lost_active) {
+  WmWindow* gained_active_wm = WmWindowAura::Get(gained_active);
+  WmWindow* lost_active_wm = WmWindowAura::Get(lost_active);
+  if (gained_active_wm)
+    set_root_window_for_new_windows(gained_active_wm->GetRootWindow());
   FOR_EACH_OBSERVER(WmActivationObserver, activation_observers_,
-                    OnWindowActivated(WmWindowAura::Get(gained_active),
-                                      WmWindowAura::Get(lost_active)));
+                    OnWindowActivated(gained_active_wm, lost_active_wm));
 }
 
 void WmShellAura::OnAttemptToReactivateWindow(aura::Window* request_active,
                                               aura::Window* actual_active) {
   FOR_EACH_OBSERVER(
       WmActivationObserver, activation_observers_,
       OnAttemptToReactivateWindow(WmWindowAura::Get(request_active),
                                   WmWindowAura::Get(actual_active)));
 }
 
 void WmShellAura::OnDisplayConfigurationChanging() {
   FOR_EACH_OBSERVER(WmDisplayObserver, display_observers_,
                     OnDisplayConfigurationChanging());
 }
 
 void WmShellAura::OnDisplayConfigurationChanged() {
   FOR_EACH_OBSERVER(WmDisplayObserver, display_observers_,
                     OnDisplayConfigurationChanged());
 }
 
 }  // namespace ash