Draggable peeking/fullscreen launcher with transparent background.

ui/app_list/views/app_list_main_view.h

 // 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.
 
 #ifndef UI_APP_LIST_VIEWS_APP_LIST_MAIN_VIEW_H_
 #define UI_APP_LIST_VIEWS_APP_LIST_MAIN_VIEW_H_
 
 #include <string>
 
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "base/timer/timer.h"
 #include "ui/app_list/app_list_export.h"
 #include "ui/app_list/app_list_model_observer.h"
 #include "ui/app_list/views/apps_grid_view_delegate.h"
 #include "ui/app_list/views/search_box_view_delegate.h"
 #include "ui/app_list/views/search_result_list_view_delegate.h"
 #include "ui/views/view.h"
 
 namespace app_list {
 
 class AppListItem;
 class AppListModel;
+class AppListView;
 class AppListViewDelegate;
 class ApplicationDragAndDropHost;
 class ContentsView;
 class PaginationModel;
 class SearchBoxView;
 
 // AppListMainView contains the normal view of the app list, which is shown
 // when the user is signed in.
 class APP_LIST_EXPORT AppListMainView : public views::View,
                                         public AppsGridViewDelegate,
                                         public AppListModelObserver,
                                         public SearchBoxViewDelegate,
                                         public SearchResultListViewDelegate {
  public:
-  explicit AppListMainView(AppListViewDelegate* delegate);
+  explicit AppListMainView(AppListViewDelegate* delegate,

[msw, 2017/06/06 17:56:31]

nit: remove explicit

[newcomer, 2017/06/06 23:26:27]

Done.

+                           AppListView* app_list_view);
   ~AppListMainView() override;
 
   void Init(gfx::NativeView parent,
             int initial_apps_page,
             SearchBoxView* search_box_view);
 
   void ShowAppListWhenReady();
 
   void ResetForShow();
 
@@ skipping 43 matching lines @@
 
   // Overridden from SearchResultListViewDelegate:
   void OnResultInstalled(SearchResult* result) override;
 
   AppListViewDelegate* delegate_;  // Owned by parent view (AppListView).
   AppListModel* model_;  // Unowned; ownership is handled by |delegate_|.
 
   // Created by AppListView. Owned by views hierarchy.
   SearchBoxView* search_box_view_;
   ContentsView* contents_view_;  // Owned by views hierarchy.
+  AppListView* const app_list_view_;  // Owned by views hierarchy.
 
   DISALLOW_COPY_AND_ASSIGN(AppListMainView);
 };
 
 }  // namespace app_list
 
 #endif  // UI_APP_LIST_VIEWS_APP_LIST_MAIN_VIEW_H_