New checks for observer crash.

content/browser/download/download_manager.cc

 // Copyright (c) 2011 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 "content/browser/download/download_manager.h"
 
 #include <iterator>
 
 #include "base/callback.h"
 #include "base/file_util.h"
@@ skipping 390 matching lines @@
     CHECK(ContainsKey(history_downloads_, download->db_handle()));
   } else {
     // TODO(rdsmith): Somewhat painful; make sure to disable in
     // release builds after resolution of http://crbug.com/85408.
     for (DownloadMap::iterator it = history_downloads_.begin();
          it != history_downloads_.end(); ++it) {
       CHECK(it->second != download);
     }
   }
 
+  int64 state = download->state();
+  base::debug::Alias(&state);
   if (ContainsKey(active_downloads_, download->id()))
     CHECK_EQ(DownloadItem::IN_PROGRESS, download->state());
   if (DownloadItem::IN_PROGRESS == download->state())
     CHECK(ContainsKey(active_downloads_, download->id()));
 }
 
 bool DownloadManager::IsDownloadReadyForCompletion(DownloadItem* download) {
   // If we don't have all the data, the download is not ready for
   // completion.
   if (!download->all_data_saved())
@@ skipping 414 matching lines @@
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   DownloadItem* download = GetActiveDownloadItem(download_id);
   if (!download)
     return;
 
   VLOG(20) << __FUNCTION__ << "()" << " db_handle = " << db_handle
            << " download_id = " << download_id
            << " download = " << download->DebugString(true);
 
   // TODO(rdsmith): Remove after http://crbug.com/85408 resolved.
-  CHECK(!ContainsKey(history_downloads_, download->db_handle()));
   int64 largest_handle = largest_db_handle_in_history_;
   base::debug::Alias(&largest_handle);
+  CHECK(!ContainsKey(history_downloads_, db_handle));
 
   AddDownloadItemToHistory(download, db_handle);
 
   // If the download is still in progress, try to complete it.
   //
   // Otherwise, download has been cancelled or interrupted before we've
   // received the DB handle.  We post one final message to the history
   // service so that it can be properly in sync with the DownloadItem's
   // completion status, and also inform any observers so that they get
   // more than just the start notification.
@@ skipping 133 matching lines @@
   if (it == save_page_downloads_.end())
     return;
 
   DownloadItem* download = it->second;
   if (!download) {
     NOTREACHED();
     return;
   }
 
   // TODO(rdsmith): Remove after http://crbug.com/85408 resolved.
-  CHECK(!ContainsKey(history_downloads_, download->db_handle()));
   int64 largest_handle = largest_db_handle_in_history_;
   base::debug::Alias(&largest_handle);
+  CHECK(!ContainsKey(history_downloads_, db_handle));
 
   AddDownloadItemToHistory(download, db_handle);
 
   // Finalize this download if it finished before the history callback.
   if (!download->IsInProgress())
     SavePageDownloadFinished(download);
 }
 
 void DownloadManager::SavePageDownloadFinished(DownloadItem* download) {
   if (download->db_handle() != DownloadItem::kUninitializedHandle) {
     delegate_->UpdateItemInPersistentStore(download);
     DCHECK(ContainsKey(save_page_downloads_, download->id()));
     save_page_downloads_.erase(download->id());
 
     if (download->IsComplete())
       NotificationService::current()->Notify(
           content::NOTIFICATION_SAVE_PACKAGE_SUCCESSFULLY_FINISHED,
           Source<DownloadManager>(this),
           Details<DownloadItem>(download));
   }
 }