Notify launcher page with onTransitionChanged event

ui/app_list/views/app_list_main_view.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 "ui/app_list/views/app_list_main_view.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/callback.h"
@@ skipping 107 matching lines @@
     AddChildView(contents_switcher_view_);
 
   search_box_view_->set_contents_view(contents_view_);
   UpdateSearchBoxVisibility();
 
   contents_view_->SetPaintToLayer(true);
   contents_view_->SetFillsBoundsOpaquely(false);
   contents_view_->layer()->SetMasksToBounds(true);
 
   delegate_->StartSearch();
+
+  FOR_EACH_OBSERVER(
+      AppListMainViewObserver, observers_, OnContentsViewCreated());
 }
 
 void AppListMainView::ShowAppListWhenReady() {
   if (pending_icon_loaders_.empty()) {
     icon_loading_wait_timer_.Stop();
     GetWidget()->Show();
     return;
   }
 
   if (icon_loading_wait_timer_.IsRunning())
@@ skipping 22 matching lines @@
 }
 
 void AppListMainView::Prerender() {
   contents_view_->Prerender();
 }
 
 void AppListMainView::ModelChanged() {
   pending_icon_loaders_.clear();
   model_ = delegate_->GetModel();
   search_box_view_->ModelChanged();
+
+  FOR_EACH_OBSERVER(
+      AppListMainViewObserver, observers_, OnContentsViewDestroying());
+
   delete contents_view_;
   contents_view_ = NULL;
   if (contents_switcher_view_) {
     delete contents_switcher_view_;
     contents_switcher_view_ = NULL;
   }
   AddContentsViews();
   Layout();
 }
 
@@ skipping 74 matching lines @@
 }
 
 void AppListMainView::NotifySearchBoxVisibilityChanged() {
   // Repaint the AppListView's background which will repaint the background for
   // the search box. This is needed because this view paints to a layer and
   // won't propagate paints upward.
   if (parent())
     parent()->SchedulePaint();
 }
 
+void AppListMainView::AddObserver(AppListMainViewObserver* observer) {
+  observers_.AddObserver(observer);
+}
+
+void AppListMainView::RemoveObserver(AppListMainViewObserver* observer) {
+  observers_.RemoveObserver(observer);
+}
+
 void AppListMainView::ActivateApp(AppListItem* item, int event_flags) {
   // TODO(jennyz): Activate the folder via AppListModel notification.
   if (item->GetItemType() == AppListFolderItem::kItemType)
     contents_view_->ShowFolderContent(static_cast<AppListFolderItem*>(item));
   else
     item->Activate(event_flags);
 }
 
 void AppListMainView::GetShortcutPathForApp(
     const std::string& app_id,
@@ skipping 28 matching lines @@
   // Resubmit the query via a posted task so that all observers for the
   // uninstall notification are notified.
   base::MessageLoop::current()->PostTask(
       FROM_HERE,
       base::Bind(&AppListMainView::QueryChanged,
                  weak_ptr_factory_.GetWeakPtr(),
                  search_box_view_));
 }
 
 }  // namespace app_list