TextEditors: Move font settings to document

Change-Id: I325764cbaa9684fa2758b0ea6c6ea58de142cb73
Reviewed-by: Eike Ziller <eike.ziller@digia.com>

src/plugins/cpptools/cppcodestylesettingspage.cpp

@@ -497,7 +497,7 @@ void CppCodeStylePreferencesWidget::decorateEditors(const TextEditor::FontSettin
     }
 
     foreach (TextEditor::SnippetEditorWidget *editor, m_previews) {
-        editor->setFontSettings(fontSettings);
+        editor->baseTextDocument()->setFontSettings(fontSettings);
         if (provider)
             provider->decorateEditor(editor);
     }