mash: Move WmShelfAura ownership to RootWindowController and init it earlier

ash/aura/wm_shelf_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/aura/wm_shelf_aura.h"
 
 #include "ash/aura/wm_window_aura.h"
 #include "ash/common/shelf/wm_shelf_observer.h"
 #include "ash/common/wm_window.h"
 #include "ash/shelf/shelf.h"
 #include "ash/shelf/shelf_layout_manager.h"
 #include "ui/views/widget/widget.h"
 
 namespace ash {
 
-WmShelfAura::WmShelfAura(Shelf* shelf)
-    : shelf_(shelf), shelf_layout_manager_(shelf->shelf_layout_manager()) {
+WmShelfAura::WmShelfAura() {}
+
+WmShelfAura::~WmShelfAura() {}
+
+void WmShelfAura::SetShelfLayoutManager(
+    ShelfLayoutManager* shelf_layout_manager) {
+  DCHECK(!shelf_layout_manager_);
+  shelf_layout_manager_ = shelf_layout_manager;
   shelf_layout_manager_->AddObserver(this);
+}
+
+void WmShelfAura::SetShelf(Shelf* shelf) {
+  DCHECK(!shelf_);
+  shelf_ = shelf;
   shelf_->AddIconObserver(this);
 }
 
-WmShelfAura::~WmShelfAura() {
-  shelf_->RemoveIconObserver(this);
-  if (shelf_layout_manager_)
-    shelf_layout_manager_->RemoveObserver(this);
+void WmShelfAura::Shutdown() {
+  if (shelf_) {
+    shelf_->RemoveIconObserver(this);
+    shelf_ = nullptr;
+  }
+
+  ResetShelfLayoutManager();
 }
 
 // static
 Shelf* WmShelfAura::GetShelf(WmShelf* shelf) {
   return static_cast<WmShelfAura*>(shelf)->shelf_;
 }
 
+void WmShelfAura::ResetShelfLayoutManager() {
+  if (!shelf_layout_manager_)
+    return;
+  shelf_layout_manager_->RemoveObserver(this);
+  shelf_layout_manager_ = nullptr;
+}
+
 WmWindow* WmShelfAura::GetWindow() {
   return WmWindowAura::Get(shelf_->shelf_widget()->GetNativeView());
 }
 
 ShelfAlignment WmShelfAura::GetAlignment() const {
   return shelf_->alignment();
 }
 
 ShelfBackgroundType WmShelfAura::GetBackgroundType() const {
   return shelf_->shelf_widget()->GetBackgroundType();
@@ skipping 19 matching lines @@
 
 void WmShelfAura::AddObserver(WmShelfObserver* observer) {
   observers_.AddObserver(observer);
 }
 
 void WmShelfAura::RemoveObserver(WmShelfObserver* observer) {
   observers_.RemoveObserver(observer);
 }
 
 void WmShelfAura::WillDeleteShelfLayoutManager() {
-  shelf_layout_manager_->RemoveObserver(this);
-  shelf_layout_manager_ = nullptr;
+  ResetShelfLayoutManager();
 }
 
 void WmShelfAura::OnBackgroundUpdated(
     ShelfBackgroundType background_type,
     BackgroundAnimatorChangeType change_type) {
   FOR_EACH_OBSERVER(WmShelfObserver, observers_,
                     OnBackgroundUpdated(background_type, change_type));
 }
 
 void WmShelfAura::WillChangeVisibilityState(ShelfVisibilityState new_state) {
   FOR_EACH_OBSERVER(WmShelfObserver, observers_,
                     WillChangeVisibilityState(new_state));
 }
 
 void WmShelfAura::OnShelfIconPositionsChanged() {
   FOR_EACH_OBSERVER(WmShelfObserver, observers_, OnShelfIconPositionsChanged());
 }
 
 }  // namespace ash