Makes WorkspaceLayoutManager use ash/wm/common types

ash/wm/aura/wm_window_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/wm/aura/wm_window_aura.h"
 
 #include "ash/screen_util.h"
 #include "ash/shelf/shelf_util.h"
 #include "ash/wm/aura/aura_layout_manager_adapter.h"
 #include "ash/wm/aura/wm_globals_aura.h"
@@ skipping 49 matching lines @@
   void SetBounds(aura::Window* window, const gfx::Rect& bounds) {
     SetChildBoundsDirect(window, bounds);
   }
 
  private:
   DISALLOW_COPY_AND_ASSIGN(BoundsSetter);
 };
 
 }  // namespace
 
-WmWindowAura::WmWindowAura(aura::Window* window) : window_(window) {
+WmWindowAura::WmWindowAura(aura::Window* window)
+    : window_(window),
+      // Mirrors that of aura::Window.
+      observers_(base::ObserverList<WmWindowObserver>::NOTIFY_EXISTING_ONLY) {
   window_->AddObserver(this);
   window_->SetProperty(kWmWindowKey, this);
 }
 
 // static
 WmWindow* WmWindow::Get(views::Widget* widget) {
   return WmWindowAura::Get(widget->GetNativeWindow());
 }
 
 // static
@@ skipping 12 matching lines @@
 std::vector<WmWindow*> WmWindowAura::FromAuraWindows(
     const std::vector<aura::Window*>& aura_windows) {
   std::vector<WmWindow*> result(aura_windows.size());
   for (size_t i = 0; i < aura_windows.size(); ++i)
     result[i] = Get(aura_windows[i]);
   return result;
 }
 
 // static
 const aura::Window* WmWindowAura::GetAuraWindow(const WmWindow* wm_window) {
-  return static_cast<const WmWindowAura*>(wm_window)->aura_window();
+  return wm_window ? static_cast<const WmWindowAura*>(wm_window)->aura_window()
+                   : nullptr;
 }
 
 const WmWindow* WmWindowAura::GetRootWindow() const {
   return Get(window_->GetRootWindow());
 }
 
 WmRootWindowController* WmWindowAura::GetRootWindowController() {
   aura::Window* root = window_->GetRootWindow();
   return root ? WmRootWindowControllerAura::Get(root) : nullptr;
 }
 
 WmGlobals* WmWindowAura::GetGlobals() const {
   return WmGlobalsAura::Get();
 }
 
 void WmWindowAura::SetName(const std::string& name) {
   window_->SetName(name);
 }
 
 void WmWindowAura::SetShellWindowId(int id) {
   window_->set_id(id);
 }
 
-int WmWindowAura::GetShellWindowId() {
+int WmWindowAura::GetShellWindowId() const {
   return window_->id();
 }
 
 ui::wm::WindowType WmWindowAura::GetType() const {
   return window_->type();
 }
 
 ui::Layer* WmWindowAura::GetLayer() {
   return window_->layer();
 }
@@ skipping 423 matching lines @@
 }
 
 void WmWindowAura::OnWindowVisibilityChanging(aura::Window* window,
                                               bool visible) {
   FOR_EACH_OBSERVER(WmWindowObserver, observers_,
                     OnWindowVisibilityChanging(this, visible));
 }
 
 }  // namespace wm
 }  // namespace ash