app_list: Add sync animation.

ui/app_list/app_list_model.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 "ui/app_list/app_list_model.h"
 
 #include "ui/app_list/app_list_item_model.h"
+#include "ui/app_list/app_list_model_observer.h"
 #include "ui/app_list/search_box_model.h"
 #include "ui/app_list/search_result.h"
 
 namespace app_list {
 
 AppListModel::AppListModel()
     : apps_(new Apps),
       search_box_(new SearchBoxModel),
       results_(new SearchResults) {

[sky, 2012/11/07 00:22:30]

Initialize status_ ?

[xiyuan, 2012/11/07 00:56:03]

Oops. Fixed.

 }
 
 AppListModel::~AppListModel() {
 }
 
+void AppListModel::AddObserver(AppListModelObserver* observer) {
+  observers_.AddObserver(observer);
+}
+
+void AppListModel::RemoveObserver(AppListModelObserver* observer) {
+  observers_.RemoveObserver(observer);
+}
+
+void AppListModel::SetStatus(Status status) {
+  if (status_ == status)
+    return;
+
+  status_ = status;
+  FOR_EACH_OBSERVER(AppListModelObserver,
+                    observers_,
+                    OnAppListModelStatusChanged());
+}
+
 }  // namespace app_list