[Downloads] Ask DownloadHistory if a download was from history.

chrome/browser/download/download_service.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_service.h"
 
 #include "base/callback.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/download/chrome_download_manager_delegate.h"
 #include "chrome/browser/download/download_history.h"
@@ skipping 47 matching lines @@
     history->GetNextDownloadId(
         manager_delegate_->GetDownloadIdReceiverCallback());
     download_history_.reset(new DownloadHistory(
         manager,
         scoped_ptr<DownloadHistory::HistoryAdapter>(
             new DownloadHistory::HistoryAdapter(history))));
   }
 
   // Pass an empty delegate when constructing the DownloadUIController. The
   // default delegate does all the notifications we need.
-  scoped_ptr<DownloadUIController::Delegate> empty_ui_delegate;
-  download_ui_.reset(new DownloadUIController(manager,
-                                              empty_ui_delegate.Pass()));
+  download_ui_.reset(new DownloadUIController(
+      manager, scoped_ptr<DownloadUIController::Delegate>()));
 
   // Include this download manager in the set monitored by the
   // global status updater.
   g_browser_process->download_status_updater()->AddManager(manager);
 
   return manager_delegate_.get();
 }
 
 DownloadHistory* DownloadService::GetDownloadHistory() {
   if (!download_manager_created_) {
@@ skipping 88 matching lines @@
     // code) when the DownloadManager is shutting down. So we shut it down
     // manually earlier. See http://crbug.com/131692
     BrowserContext::GetDownloadManager(profile_)->Shutdown();
   }
 #if !defined(OS_ANDROID)
   extension_event_router_.reset();
 #endif
   manager_delegate_.reset();
   download_history_.reset();
 }