Download shelf autohides on showing in shell, just same as regular open

chrome/browser/extensions/api/downloads/downloads_api_browsertest.cc

Index: chrome/browser/extensions/api/downloads/downloads_api_browsertest.cc
diff --git a/chrome/browser/extensions/api/downloads/downloads_api_browsertest.cc b/chrome/browser/extensions/api/downloads/downloads_api_browsertest.cc
index a8a9eca778bc7557fd472d364cbfbdb39a68cf5b..9d0e6ec97cb70492c5aa5adb7f887ff37e3d9760 100644
--- a/chrome/browser/extensions/api/downloads/downloads_api_browsertest.cc
+++ b/chrome/browser/extensions/api/downloads/downloads_api_browsertest.cc
@@ -29,6 +29,7 @@
 #include "chrome/browser/extensions/extension_apitest.h"
 #include "chrome/browser/extensions/extension_function_test_utils.h"
 #include "chrome/browser/net/url_request_mock_util.h"
+#include "chrome/browser/platform_util_internal.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_tabstrip.h"
@@ -325,6 +326,8 @@ class DownloadExtensionTest : public ExtensionApiTest {
     // Disable file chooser for current profile.
     DownloadTestFileActivityObserver observer(current_browser()->profile());
     observer.EnableFileChooser(false);
+    // Prevent platform from opening files and showing folders.
+    platform_util::internal::DisableShellOperationsForTesting();
   }
 
   void GoOnTheRecord() { current_browser_ = browser(); }