mash: Replace ShelfItemDelegate::CanPin with ShelfItem::pinned_by_policy.

ash/common/shelf/shelf_item_delegate.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 ASH_COMMON_SHELF_SHELF_ITEM_DELEGATE_H_
 #define ASH_COMMON_SHELF_SHELF_ITEM_DELEGATE_H_
 
 #include "ash/ash_export.h"
 #include "base/strings/string16.h"
 
@@ skipping 29 matching lines @@
   // and has an instance of |views::View| as the event target
   // but not |aura::Window|. If the |event| is of type KeyEvent, it is assumed
   // that this was triggered by keyboard action (Alt+<number>) and special
   // handling might happen.
   // Returns the action performed by selecting the item.
   virtual PerformedAction ItemSelected(const ui::Event& event) = 0;
 
   // Returns the title to display.
   virtual base::string16 GetTitle() = 0;
 
-  // Returns whether the user can change the pin status of this item.
-  // Pinning may be disallowed by policy if this app is pinned by pre-defined
-  // pinned app list.
-  virtual bool CanPin() const = 0;

[James Cook, 2017/01/04 17:32:17]

Wow, the old code was confusing. This should have been CanUnpin(). I like your
approach better.

[msw, 2017/01/04 22:23:04]

Acknowledged.

-
   // Returns the application menu model for the specified item. There are three
   // possible return values:
   //  - A return of NULL indicates that no menu is wanted for this item.
   //  - A return of a menu with one item means that only the name of the
   //    application/item was added and there are no active applications.
   //    Note: This is useful for hover menus which also show context help.
   //  - A list containing the title and the active list of items.
   // The caller takes ownership of the returned model.
   // |event_flags| specifies the flags of the event which triggered this menu.
   virtual ShelfMenuModel* CreateApplicationMenu(int event_flags) = 0;
 
   // Closes all windows associated with this item.
   virtual void Close() = 0;
 };
 
 }  // namespace ash
 
 #endif  // ASH_COMMON_SHELF_SHELF_ITEM_DELEGATE_H_