chromeos: Eliminate WmWindow from //ash/system

ash/system/palette/palette_tool_manager.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/system/palette/palette_tool_manager.h"
 
 #include <algorithm>
 
 #include "ash/resources/vector_icons/vector_icons.h"
 #include "ash/system/palette/palette_tool.h"
@@ skipping 110 matching lines @@
 }
 
 void PaletteToolManager::HidePalette() {
   delegate_->HidePalette();
 }
 
 void PaletteToolManager::HidePaletteImmediately() {
   delegate_->HidePaletteImmediately();
 }
 
-WmWindow* PaletteToolManager::GetWindow() {
+aura::Window* PaletteToolManager::GetWindow() {
   return delegate_->GetWindow();
 }
 
 void PaletteToolManager::RecordPaletteOptionsUsage(PaletteTrayOptions option) {
   return delegate_->RecordPaletteOptionsUsage(option);
 }
 
 void PaletteToolManager::RecordPaletteModeCancellation(
     PaletteModeCancelType type) {
   return delegate_->RecordPaletteModeCancellation(type);
 }
 
 PaletteTool* PaletteToolManager::FindToolById(PaletteToolId tool_id) const {
   for (const std::unique_ptr<PaletteTool>& tool : tools_) {
     if (tool->GetToolId() == tool_id)
       return tool.get();
   }
 
   return nullptr;
 }
 
 }  // namespace ash