[MD settings] adding c++ side of font settings

chrome/browser/ui/webui/settings/font_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 CHROME_BROWSER_UI_WEBUI_SETTINGS_FONT_HANDLER_H_
+#define CHROME_BROWSER_UI_WEBUI_SETTINGS_FONT_HANDLER_H_
+
+#include "base/macros.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
+#include "chrome/browser/ui/webui/settings/md_settings_ui.h"
+
+namespace base {
+class ListValue;
+}
+
+namespace content {
+class WebUI;
+}
+
+namespace settings {
+
+// Handle OS font list, font preference settings and character encoding.
+class FontHandler : public SettingsPageUIHandler {
+ public:
+  explicit FontHandler(content::WebUI* webui);
+  ~FontHandler() override;
+
+  // SettingsPageUIHandler implementation.
+  void RegisterMessages() override;
+
+ private:
+  // Handler for script asking for font information.
+  void HandleFetchFontsData(const base::ListValue* args);
+
+  // Callback to handle fonts loading.
+  void FontListHasLoaded(scoped_ptr<base::ListValue> list);
+
+  base::WeakPtrFactory<FontHandler> weak_ptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(FontHandler);
+};
+
+}  // namespace settings
+
+#endif  // CHROME_BROWSER_UI_WEBUI_SETTINGS_FONT_HANDLER_H_