Reland DownloadItem::Observer::OnDownloadDestroyed() replaces DownloadItem::REMOVING

chrome/browser/download/download_item_model.cc

 // 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.
 
 #include "chrome/browser/download/download_item_model.h"
 
 #include "base/i18n/number_formatting.h"
 #include "base/i18n/rtl.h"
 #include "base/string16.h"
 #include "base/sys_string_conversions.h"
@@ skipping 110 matching lines @@
     case DownloadItem::COMPLETE:
       if (download_->GetFileExternallyRemoved()) {
         status_text = l10n_util::GetStringUTF16(IDS_DOWNLOAD_STATUS_REMOVED);
       } else {
         status_text.clear();
       }
       break;
     case DownloadItem::CANCELLED:
       status_text = l10n_util::GetStringUTF16(IDS_DOWNLOAD_STATUS_CANCELLED);
       break;
-    case DownloadItem::REMOVING:

[Randy Smith (Not in Mondays), 2012/06/29 19:34:54]

Asanka, what protection is there in DownloadItemModel for not continuing to
observer DownloadItems after they've been destroyed?

[asanka, 2012/07/11 18:12:19]

DownloadItemModel doesn't observe DownloadItems. It merely helps interpret the
current state of the DownloadItem. Currently it is the responsibility of the
owner of the download item model to make sure the model doesn't outlive the
download item.

-      break;
     case DownloadItem::INTERRUPTED:
       reason = download_->GetLastReason();
       status_text = InterruptReasonStatusMessage(reason);
       if (total <= 0) {
         size_text = ui::FormatBytes(size);
       } else {
         size_text = l10n_util::GetStringFUTF16(IDS_DOWNLOAD_RECEIVED_SIZE,
                                                simple_size,
                                                simple_total);
       }
@@ skipping 218 matching lines @@
       break;
     default:
       string_id = IDS_DOWNLOAD_INTERRUPTED_STATUS;
       break;
   }
 
   status_text = l10n_util::GetStringUTF16(string_id);
 
   return status_text;
 }