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

components/proximity_auth/webui/proximity_auth_webui_handler.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_WEBUI_HANDLER_H_
+#define COMPONENTS_PROXIMITY_AUTH_WEBUI_PROXIMITY_AUTH_WEBUI_HANDLER_H_
+
+#include "content/public/browser/web_ui_message_handler.h"
+
+namespace proximity_auth {
+
+class ProximityAuthService;
+
+// Handles messages from the chrome://proximity-auth page.
+class ProximityAuthWebUIHandler : public content::WebUIMessageHandler {
+ public:
+  ProximityAuthWebUIHandler();
+  ~ProximityAuthWebUIHandler() override;
+
+  // content::WebUIMessageHandler implementation.
+  void RegisterMessages() override;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(ProximityAuthWebUIHandler);
+};
+
+}  // namespace proximity_auth
+
+#endif  // COMPONENTS_PROXIMITY_AUTH_WEBUI_PROXIMITY_AUTH_WEBUI_HANDLER_H_