Replace WmWindowObserver with aura::WindowObserver.

ash/common/wm/workspace_controller.cc

 // Copyright (c) 2012 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/workspace_controller.h"
 
 #include <utility>
 
 #include "ash/common/shelf/wm_shelf.h"
 #include "ash/common/wm/dock/docked_window_layout_manager.h"
@@ skipping 20 matching lines @@
 
 // The duration of the animation that occurs on first login.
 const int kInitialAnimationDurationMS = 200;
 
 }  // namespace
 
 WorkspaceController::WorkspaceController(WmWindow* viewport)
     : viewport_(viewport),
       event_handler_(WmShell::Get()->CreateWorkspaceEventHandler(viewport)),
       layout_manager_(new WorkspaceLayoutManager(viewport)) {
-  viewport_->AddObserver(this);
+  viewport_->aura_window()->AddObserver(this);
   viewport_->SetVisibilityAnimationTransition(::wm::ANIMATE_NONE);
   viewport_->SetLayoutManager(base::WrapUnique(layout_manager_));
 }
 
 WorkspaceController::~WorkspaceController() {
   if (!viewport_)
     return;
 
-  viewport_->RemoveObserver(this);
+  viewport_->aura_window()->RemoveObserver(this);
   viewport_->SetLayoutManager(nullptr);
 }
 
 wm::WorkspaceWindowState WorkspaceController::GetWindowState() const {
   if (!viewport_ || !viewport_->GetRootWindowController()->HasShelf())
     return wm::WORKSPACE_WINDOW_STATE_DEFAULT;
 
   const WmWindow* fullscreen = wm::GetWindowForFullscreenMode(viewport_);
   if (fullscreen && !fullscreen->GetWindowState()->ignored_by_shelf())
     return wm::WORKSPACE_WINDOW_STATE_FULL_SCREEN;
@@ skipping 54 matching lines @@
     layer->SetTransform(gfx::Transform());
     layer->SetOpacity(1.0f);
   }
 }
 
 void WorkspaceController::SetMaximizeBackdropDelegate(
     std::unique_ptr<WorkspaceLayoutManagerBackdropDelegate> delegate) {
   layout_manager_->SetMaximizeBackdropDelegate(std::move(delegate));
 }
 
-void WorkspaceController::OnWindowDestroying(WmWindow* window) {
-  DCHECK_EQ(window, viewport_);
-  viewport_->RemoveObserver(this);
+void WorkspaceController::OnWindowDestroying(aura::Window* window) {
+  DCHECK_EQ(WmWindow::Get(window), viewport_);
+  viewport_->aura_window()->RemoveObserver(this);
   viewport_ = nullptr;
   // Destroy |event_handler_| too as it depends upon |window|.
   event_handler_.reset();
   layout_manager_ = nullptr;
 }
 
 }  // namespace ash