[Mac] Inform reference counted objects that hold a weak Browser* when the Browser is being destroye…

chrome/browser/ui/cocoa/download/download_shelf_controller.h

 // 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.
 
 #import <Cocoa/Cocoa.h>
 
 #include "base/mac/scoped_nsobject.h"
 #include "base/memory/scoped_ptr.h"
+#import "chrome/browser/ui/cocoa/has_weak_browser_pointer.h"
 #import "chrome/browser/ui/cocoa/view_resizer.h"
 #include "ui/base/cocoa/tracking_area.h"
 
 @class AnimatableView;
 class Browser;
 @class BrowserWindowController;
 @class DownloadItemController;
 class DownloadShelf;
 @class DownloadShelfView;
 @class HyperlinkButtonCell;
@@ skipping 14 matching lines @@
 // download_shelf_controller for the shelf (this file). The shelf's background
 // is drawn by download_shelf_view. Every item in a shelf is controlled by a
 // download_item_controller.
 //
 // download_item_mac bridges calls from chromium's c++ world to the objc
 // download_item_controller, which is responsible for managing a single item
 // on the shelf. The item controller loads its UI from a xib file, where the
 // UI of an item itself is represented by a button that is drawn by
 // download_item_cell.
 
-@interface DownloadShelfController : NSViewController<NSTextViewDelegate> {
+@interface DownloadShelfController
+    : NSViewController<NSTextViewDelegate, HasWeakBrowserPointer> {
  @private
   IBOutlet HoverButton* hoverCloseButton_;
 
   // YES if the download shelf is intended to be displayed. The shelf animates
   // out when it is closing. During this time, barIsVisible_ is NO although the
   // shelf is still visible on screen.
   BOOL barIsVisible_;
 
   // YES if the containing browser window is fullscreen.
   BOOL isFullscreen_;
@@ skipping 59 matching lines @@
 
 // Similar to addDownloadItem above, but adds a DownloadItemController.
 - (void)add:(DownloadItemController*)download;
 
 // Remove a download, possibly via clearing browser data.
 - (void)remove:(DownloadItemController*)download;
 
 // Called by individual item controllers when their downloads are opened.
 - (void)downloadWasOpened:(DownloadItemController*)download;
 
-// Notification that the download shelf is going to be destroyed and should
-// release the downloads.
-- (void)exiting;
-
 // Return the height of the download shelf.
 - (float)height;
 
 // Re-layouts all download items based on their current state.
 - (void)layoutItems;
 
 @end