BrowserContext should simply own DownloadManager

chrome/browser/download/download_browsertest.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 <sstream>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/file_util.h"
 #include "base/files/file_path.h"
@@ skipping 2624 matching lines @@
   // Check that the file contains the expected referrer.
   base::FilePath file(download_items[0]->GetTargetFilePath());
   std::string expected_contents = test_server()->GetURL(std::string()).spec();
   ASSERT_TRUE(VerifyFile(file, expected_contents, expected_contents.length()));
 }
 
 IN_PROC_BROWSER_TEST_F(DownloadTest, HiddenDownload) {
   base::FilePath file(FILE_PATH_LITERAL("download-test1.lib"));
   GURL url(URLRequestMockHTTPJob::GetMockUrl(file));
 
-  scoped_refptr<DownloadManager> download_manager =
-      DownloadManagerForBrowser(browser());
+  DownloadManager* download_manager = DownloadManagerForBrowser(browser());
   scoped_ptr<content::DownloadTestObserver> observer(
       new content::DownloadTestObserverTerminal(
           download_manager,
           1,
           content::DownloadTestObserver::ON_DANGEROUS_DOWNLOAD_FAIL));
 
   // Download and set IsHiddenDownload to true.
   WebContents* web_contents =
       browser()->tab_strip_model()->GetActiveWebContents();
   scoped_ptr<DownloadUrlParameters> params(
@@ skipping 279 matching lines @@
   scoped_ptr<content::DownloadTestObserver> observer(
       DangerousDownloadWaiter(
           browser(), 1,
           content::DownloadTestObserver::ON_DANGEROUS_DOWNLOAD_DENY));
   ui_test_utils::NavigateToURL(browser(), url);
   observer->WaitForFinished();
   EXPECT_EQ(1u, observer->NumDownloadsSeenInState(DownloadItem::CANCELLED));
   EXPECT_EQ(1u, observer->NumDangerousDownloadsSeen());
   EXPECT_FALSE(browser()->window()->IsDownloadShelfVisible());
 }