Add new chrome://proximity-auth WebUI for debugging Smart Lock.

components/proximity_auth/webui/proximity_auth_ui.h

+// 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.
+
+#ifndef COMPONENTS_PROXIMITY_AUTH_WEBUI_PROXIMITY_AUTH_UI_H_
+#define COMPONENTS_PROXIMITY_AUTH_WEBUI_PROXIMITY_AUTH_UI_H_
+
+#include <string>
+
+#include "content/public/browser/web_ui_controller.h"
+
+namespace proximity_auth {
+
+class ProximityAuthService;
+
+// The WebUI controller for chrome://proximity-auth.
+class ProximityAuthUI : public content::WebUIController {
+ public:
+  // Note: |web_ui| is not owned by this instance.
+  explicit ProximityAuthUI(content::WebUI* web_ui);
+  ~ProximityAuthUI() override;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(ProximityAuthUI);
+};
+
+}  // namespace proximity_auth
+
+#endif  // COMPONENTS_PROXIMITY_AUTH_WEBUI_PROXIMITY_AUTH_UI_H_