Refactor PanelLayoutManager to use aura::LayoutManager

ash/common/wm/wm_snap_to_pixel_layout_manager.cc

 // Copyright 2014 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/common/wm/wm_snap_to_pixel_layout_manager.h"
 
 #include "ash/common/wm_window.h"
 #include "ash/public/cpp/shell_window_ids.h"
 #include "ash/wm/window_properties.h"
 #include "base/memory/ptr_util.h"
 #include "ui/aura/window.h"
 
 namespace ash {
 namespace wm {
 
 WmSnapToPixelLayoutManager::WmSnapToPixelLayoutManager() {}
 
 WmSnapToPixelLayoutManager::~WmSnapToPixelLayoutManager() {}
 
 // static
 void WmSnapToPixelLayoutManager::InstallOnContainers(WmWindow* window) {
   for (WmWindow* child : window->GetChildren()) {
     if (child->GetShellWindowId() < kShellWindowId_Min ||
         child->GetShellWindowId() > kShellWindowId_Max)  // not a container
       continue;
     if (child->aura_window()->GetProperty(kSnapChildrenToPixelBoundary)) {
-      if (!child->GetLayoutManager())
+      if (!child->GetLayoutManager() && !child->aura_window()->layout_manager())
         child->SetLayoutManager(base::MakeUnique<WmSnapToPixelLayoutManager>());
     } else {
       InstallOnContainers(child);
     }
   }
 }
 
 void WmSnapToPixelLayoutManager::OnWindowResized() {}
 
 void WmSnapToPixelLayoutManager::OnWindowAddedToLayout(WmWindow* child) {}
 
 void WmSnapToPixelLayoutManager::OnWillRemoveWindowFromLayout(WmWindow* child) {
 }
 
 void WmSnapToPixelLayoutManager::OnWindowRemovedFromLayout(WmWindow* child) {}
 
 void WmSnapToPixelLayoutManager::OnChildWindowVisibilityChanged(WmWindow* child,
                                                                 bool visibile) {
 }
 
 void WmSnapToPixelLayoutManager::SetChildBounds(
     WmWindow* child,
     const gfx::Rect& requested_bounds) {
   child->SetBoundsDirect(requested_bounds);
   child->SnapToPixelBoundaryIfNecessary();
 }
 
 }  // namespace wm
 }  // namespace ash