Hide the "downloads" page policy disabled UI elements from supervised users

chrome/browser/ui/webui/downloads_ui.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/ui/webui/downloads_ui.h"
 
 #include "base/memory/ref_counted_memory.h"
 #include "base/memory/singleton.h"
 #include "base/prefs/pref_service.h"
 #include "base/strings/string_piece.h"
@@ skipping 63 matching lines @@
   source->AddLocalizedString("control_cancel", IDS_DOWNLOAD_LINK_CANCEL);
   source->AddLocalizedString("control_resume", IDS_DOWNLOAD_LINK_RESUME);
   source->AddLocalizedString("control_removefromlist",
                              IDS_DOWNLOAD_LINK_REMOVE);
   source->AddLocalizedString("control_by_extension",
                              IDS_DOWNLOAD_BY_EXTENSION);
 
   PrefService* prefs = profile->GetPrefs();
   source->AddBoolean("allow_deleting_history",
                      prefs->GetBoolean(prefs::kAllowDeletingBrowserHistory));
+  source->AddBoolean("show_delete_history", !profile->IsManaged());
 
   source->SetJsonPath("strings.js");
   source->AddResourcePath("downloads.css", IDR_DOWNLOADS_CSS);
   source->AddResourcePath("downloads.js", IDR_DOWNLOADS_JS);
   source->SetDefaultResource(IDR_DOWNLOADS_HTML);
   source->SetUseJsonJSFormatV2();
 
   return source;
 }
 
@@ skipping 20 matching lines @@
   content::URLDataSource::Add(profile, theme);
 #endif
 }
 
 // static
 base::RefCountedMemory* DownloadsUI::GetFaviconResourceBytes(
       ui::ScaleFactor scale_factor) {
   return ResourceBundle::GetSharedInstance().
       LoadDataResourceBytesForScale(IDR_DOWNLOADS_FAVICON, scale_factor);
 }