No need to pass DownloadItemModel ownership.

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

 // 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 "chrome/browser/ui/cocoa/download/download_shelf_controller.h"
 
 #include "base/mac/bundle_locations.h"
 #include "base/mac/mac_util.h"
 #include "base/sys_string_conversions.h"
 #include "chrome/browser/download/download_util.h"
@@ skipping 274 matching lines @@
       [[[itemController view] animator] setFrame:frame];
     currentX += frame.size.width + kDownloadItemPadding;
     skipFirst = NO;
   }
 }
 
 - (void)layoutItems {
   [self layoutItems:NO];
 }
 
-- (void)addDownloadItem:(DownloadItemModel*)model {
+- (void)addDownloadItem:(DownloadItem*)downloadItem {
   DCHECK([NSThread isMainThread]);
   [self cancelAutoCloseAndRemoveTrackingArea];
 
   // Insert new item at the left.
   scoped_nsobject<DownloadItemController> controller(
-      [[DownloadItemController alloc] initWithModel:model
-                                              shelf:self
-                                          navigator:navigator_]);
+      [[DownloadItemController alloc] initWithDownload:downloadItem
+                                                 shelf:self
+                                             navigator:navigator_]);
 
   // Adding at index 0 in NSMutableArrays is O(1).
   [downloadItemControllers_ insertObject:controller.get() atIndex:0];
 
   [itemContainerView_ addSubview:[controller view]];
 
   // The controller is in charge of removing itself as an observer in its
   // dealloc.
   [[NSNotificationCenter defaultCenter]
     addObserver:controller
@@ skipping 146 matching lines @@
   }
 
   // Set the tracking off to create a new tracking area for the control.
   // When changing the bounds/frame on a HoverButton, the tracking isn't updated
   // correctly, it needs to be turned off and back on.
   [hoverCloseButton_ setTrackingEnabled:NO];
   [hoverCloseButton_ setFrame:bounds];
   [hoverCloseButton_ setTrackingEnabled:YES];
 }
 @end