Cleanup ExtensionDownloadsEventRouter on download manager shutdown

chrome/browser/download/chrome_download_manager_delegate.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/chrome_download_manager_delegate.h"
 
 #include <string>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 126 matching lines @@
                  base::Unretained(dm)));
 #if !defined(OS_ANDROID)
   extension_event_router_.reset(new ExtensionDownloadsEventRouter(
       profile_, download_manager_));
 #endif
 }
 
 void ChromeDownloadManagerDelegate::Shutdown() {
   download_history_.reset();
   download_prefs_.reset();
+#if !defined(OS_ANDROID)
+  extension_event_router_.reset();
+#endif
 }
 
 DownloadId ChromeDownloadManagerDelegate::GetNextId() {
   if (!profile_->IsOffTheRecord())
     return DownloadId(this, next_download_id_++);
 
   return BrowserContext::GetDownloadManager(profile_->GetOriginalProfile())->
       GetDelegate()->GetNextId();
 }
 
@@ skipping 660 matching lines @@
     int32 download_id, int64 db_handle) {
   // It's not immediately obvious, but HistoryBackend::CreateDownload() can
   // call this function with an invalid |db_handle|. For instance, this can
   // happen when the history database is offline. We cannot have multiple
   // DownloadItems with the same invalid db_handle, so we need to assign a
   // unique |db_handle| here.
   if (db_handle == DownloadItem::kUninitializedHandle)
     db_handle = download_history_->GetNextFakeDbHandle();
   download_manager_->OnItemAddedToPersistentStore(download_id, db_handle);
 }