Add a basic stub Polymer settings page at chrome://md-settings.

chrome/browser/ui/webui/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/md_settings_ui.h"
+
+#include <string>
+
+#include "base/values.h"
+#include "chrome/common/url_constants.h"
+#include "chrome/grit/generated_resources.h"
+#include "content/public/browser/web_contents.h"
+#include "content/public/browser/web_ui.h"
+#include "content/public/browser/web_ui_data_source.h"
+#include "grit/browser_resources.h"
+
+MdSettingsUI::MdSettingsUI(content::WebUI* web_ui)
+    : content::WebUIController(web_ui) {
+  content::WebUIDataSource* html_source =
+      content::WebUIDataSource::Create(chrome::kChromeUIMdSettingsHost);
+
+  html_source->SetDefaultResource(IDR_MD_SETTINGS_UI_HTML);
+
+  content::WebUIDataSource::Add(web_ui->GetWebContents()->GetBrowserContext(),
+                                html_source);
+}
+
+MdSettingsUI::~MdSettingsUI() {
+}