[iOS] Support for chrome://version

ios/chrome/browser/ui/webui/version_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 IOS_CHROME_BROWSER_UI_WEBUI_VERSION_HANDLER_H_
+#define IOS_CHROME_BROWSER_UI_WEBUI_VERSION_HANDLER_H_
+
+#include "base/macros.h"
+#include "ios/public/provider/web/web_ui_ios_message_handler.h"
+
+namespace base {
+class ListValue;
+}
+
+// Handler class for Version page operations.
+class VersionHandler : public web::WebUIIOSMessageHandler {
+ public:
+  VersionHandler();
+  ~VersionHandler() override;
+
+  // content::WebUIMessageHandler implementation.
+  void RegisterMessages() override;
+
+  // Callback for the "requestVersionInfo" message. This asynchronously requests
+  // the list of variations.
+  void HandleRequestVersionInfo(const base::ListValue* args);
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(VersionHandler);
+};
+
+#endif  // IOS_CHROME_BROWSER_UI_WEBUI_VERSION_HANDLER_H_