Remove ash::ScopedObserverWithDuplicatedSources

ash/shelf/shelf_window_watcher.cc

 // Copyright 2013 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/shelf/shelf_window_watcher.h"
 
 #include <memory>
 #include <utility>
 
 #include "ash/aura/wm_window_aura.h"
@@ skipping 87 matching lines @@
   DCHECK(HasShelfItemForWindow(window));
   window_watcher_->FinishObservingRemovedWindow(window);
 }
 
 ShelfWindowWatcher::ShelfWindowWatcher(ShelfModel* model)
     : model_(model),
       root_window_observer_(this),
       removed_window_observer_(this),
       observed_windows_(this),
       observed_root_windows_(&root_window_observer_),
-      observed_removed_windows_(&removed_window_observer_),
-      observed_activation_clients_(this) {
-  // We can't assume all RootWindows have the same ActivationClient.
-  // Add a RootWindow and its ActivationClient to the observed list.
+      observed_removed_windows_(&removed_window_observer_) {
+  Shell::GetInstance()->activation_client()->AddObserver(this);

[James Cook, 2016/07/26 17:48:31]

This will get converted to WmShell in my next CL. I kept ash::Shell here to keep
this CL simpler.

   for (aura::Window* root : Shell::GetAllRootWindows())
     OnRootWindowAdded(WmWindowAura::Get(root));
 
   display::Screen::GetScreen()->AddObserver(this);
 }
 
 ShelfWindowWatcher::~ShelfWindowWatcher() {
   display::Screen::GetScreen()->RemoveObserver(this);
+  Shell::GetInstance()->activation_client()->RemoveObserver(this);
 }
 
 void ShelfWindowWatcher::AddShelfItem(aura::Window* window) {
   const ShelfItemDetails* item_details = GetShelfItemDetailsForWindow(window);
   ShelfItem item;
   ShelfID id = model_->next_id();
   item.status = wm::IsActiveWindow(window) ? STATUS_ACTIVE : STATUS_RUNNING;
   SetShelfItemDetailsForShelfItem(&item, *item_details);
   SetShelfIDForWindow(id, window);
   std::unique_ptr<ShelfItemDelegate> item_delegate(
       new ShelfWindowWatcherItemDelegate(window));
   model_->SetShelfItemDelegate(id, std::move(item_delegate));
   model_->Add(item);
 }
 
 void ShelfWindowWatcher::RemoveShelfItem(aura::Window* window) {
   model_->RemoveItemAt(model_->ItemIndexByID(GetShelfIDForWindow(window)));
   SetShelfIDForWindow(kInvalidShelfID, window);
 }
 
 void ShelfWindowWatcher::OnRootWindowAdded(WmWindow* root_window_wm) {
   aura::Window* root_window = WmWindowAura::GetAuraWindow(root_window_wm);
-  // |observed_activation_clients_| can have the same ActivationClient multiple
-  // times - which would be handled by the |observed_activation_clients_|.
-  observed_activation_clients_.Add(
-      aura::client::GetActivationClient(root_window));
   observed_root_windows_.Add(root_window);
 
   aura::Window* default_container =
       Shell::GetContainer(root_window, kShellWindowId_DefaultContainer);
   observed_windows_.Add(default_container);
   for (size_t i = 0; i < default_container->children().size(); ++i)
     observed_windows_.Add(default_container->children()[i]);
 }
 
 void ShelfWindowWatcher::OnRootWindowRemoved(aura::Window* root_window) {
   observed_root_windows_.Remove(root_window);
-  observed_activation_clients_.Remove(
-      aura::client::GetActivationClient(root_window));
 }
 
 void ShelfWindowWatcher::UpdateShelfItemStatus(aura::Window* window,
                                                bool is_active) {
   int index = GetShelfItemIndexForWindow(window);
   DCHECK_GE(index, 0);
 
   ShelfItem item = model_->items()[index];
   item.status = is_active ? STATUS_ACTIVE : STATUS_RUNNING;
   model_->Set(index, item);
@@ skipping 103 matching lines @@
   // When this is called, RootWindow of |old_display| is already removed.
   // Instead, we remove an observer from RootWindow and ActivationClient in the
   // OnRootWindowDestroyed().
   // Do nothing here.
 }
 
 void ShelfWindowWatcher::OnDisplayMetricsChanged(const display::Display&,
                                                  uint32_t) {}
 
 }  // namespace ash