[Mac] DownloadShelf should be notified when autoclosing.

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/memory/scoped_nsobject.h"
 #include "base/memory/scoped_ptr.h"
 #import "chrome/browser/ui/cocoa/view_resizer.h"
 
@@ skipping 59 matching lines @@
   // Delegate that handles resizing our view.
   id<ViewResizer> resizeDelegate_;
 
   // Used for loading pages.
   content::PageNavigator* navigator_;
 };
 
 - (id)initWithBrowser:(Browser*)browser
        resizeDelegate:(id<ViewResizer>)resizeDelegate;
 
+// Run when the user clicks the 'Show All' button.
 - (IBAction)showDownloadsTab:(id)sender;
 
+// Run when the user clicks the close button on the right side of the shelf.
+- (IBAction)handleClose:(id)sender;
+
+// Shows or hides the download shelf based on the value of |show|.
+// |isUserAction| should be YES if the operation is being triggered based on a
+// user action (currently only relevant when hiding the shelf).
+// Note: This is intended to be invoked from DownloadShelfMac. If invoked
+// directly, the shelf visibility state maintained by DownloadShelf and the
+// owning Browser will not be updated.
+- (void)showDownloadShelf:(BOOL)show
+             isUserAction:(BOOL)isUserAction;
+
 // Returns our view cast as an AnimatableView.
 - (AnimatableView*)animatableView;
 
 - (DownloadShelf*)bridge;
 - (BOOL)isVisible;
 
-- (IBAction)show:(id)sender;
-
-// Run when the user clicks the close button on the right side of the shelf.
-- (IBAction)hide:(id)sender;
-
+// Add a new download item to the leftmost position of the download shelf. The
+// item should not have been already added to this shelf.
 - (void)addDownloadItem:(content::DownloadItem*)downloadItem;
 
 // 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 we are closing and should release our 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