MD Settings: Add a <base> tag in settings.html.

chrome/browser/ui/webui/settings/md_settings_ui.cc

 // Copyright 2015 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/settings/md_settings_ui.h"
 
 #include <stddef.h>
 
 #include <string>
 
@@ skipping 123 matching lines @@
   AddSettingsPageUIHandler(base::MakeUnique<SystemHandler>());
 #endif
 
   // Host must be derived from the visible URL, since this might be serving
   // either chrome://settings or chrome://md-settings.
   CHECK(url.GetOrigin() == GURL(chrome::kChromeUISettingsURL).GetOrigin() ||
         url.GetOrigin() == GURL(chrome::kChromeUIMdSettingsURL).GetOrigin());
 
   content::WebUIDataSource* html_source =
       content::WebUIDataSource::Create(url.host());
+  html_source->AddString("hostname", url.host());
 
 #if defined(OS_CHROMEOS)
   chromeos::settings::EasyUnlockSettingsHandler* easy_unlock_handler =
       chromeos::settings::EasyUnlockSettingsHandler::Create(html_source,
                                                             profile);
   if (easy_unlock_handler)
     AddSettingsPageUIHandler(base::WrapUnique(easy_unlock_handler));
 
   AddSettingsPageUIHandler(base::WrapUnique(
       chromeos::settings::DateTimeHandler::Create(html_source)));
@@ skipping 62 matching lines @@
   UMA_HISTOGRAM_TIMES("Settings.LoadDocumentTime.MD",
                       base::Time::Now() - load_start_time_);
 }
 
 void MdSettingsUI::DocumentOnLoadCompletedInMainFrame() {
   UMA_HISTOGRAM_TIMES("Settings.LoadCompletedTime.MD",
                       base::Time::Now() - load_start_time_);
 }
 
 }  // namespace settings