Refactors StackingController::GetDefaultParent to ash/wm/common

ash/wm/common/wm_shell_window_ids.h

 // 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.
 
 #ifndef ASH_WM_COMMON_WM_SHELL_WINDOW_IDS_H_
 #define ASH_WM_COMMON_WM_SHELL_WINDOW_IDS_H_
 
 // Defines the ids assigned to known containers. The id for a WmWindow is
 // accessed via GetShellWindowId().
 
 // TODO(sky): move this into wm namespace.
 namespace ash {
 
 // NOTE: while the value of these is not necessarily important, the ordering
 // is and is enforced in ash/shell_window_ids.h.
 
+// A container used for windows of WINDOW_TYPE_CONTROL that have no parent.
+// This container is not visible.
+const int kShellWindowId_UnparentedControlContainer = 3;
+
 // The container for standard top-level windows.
 const int kShellWindowId_DefaultContainer = 6;
 
 // The container for top-level windows with the 'always-on-top' flag set.
 const int kShellWindowId_AlwaysOnTopContainer = 7;
 
 // The container for windows docked to either side of the desktop.
 const int kShellWindowId_DockedContainer = 8;
 
 // The container for the shelf.
 const int kShellWindowId_ShelfContainer = 9;
 
 // The container for panel windows.
 const int kShellWindowId_PanelContainer = 11;
 
 // TODO(sky): this seems unnecessary. Perhaps it should be injected?
 // The container for the app list.
 const int kShellWindowId_AppListContainer = 12;
 
+// The container for user-specific modal windows.
+const int kShellWindowId_SystemModalContainer = 13;
+
+// The container for the lock screen.
+const int kShellWindowId_LockScreenContainer = 15;
+
+// The container for the lock screen modal windows.
+const int kShellWindowId_LockSystemModalContainer = 16;
+
+// The container for menus.
+const int kShellWindowId_MenuContainer = 19;
+
+// The container for drag/drop images and tooltips.
+const int kShellWindowId_DragImageAndTooltipContainer = 20;
+
 // ID of the window created by PhantomWindowController or DragWindowController.
 const int kShellWindowId_PhantomWindow = 23;
 
 }  // namespace ash
 
 #endif  // ASH_WM_COMMON_WM_SHELL_WINDOW_IDS_H_