This patch restores intelligent SELECT popup placement in X11.

See:
    https://bugs.webkit.org/show_bug.cgi?id=210069
    https://bugs.webkit.org/show_bug.cgi?id=210603


--- a/Source/WebKit/UIProcess/gtk/WebPopupMenuProxyGtk.cpp	2020-04-17 19:23:25.000000000 +0000
+++ b/Source/WebKit/UIProcess/gtk/WebPopupMenuProxyGtk.cpp	2020-04-18 09:51:36.361498353 +0000
@@ -339,7 +339,7 @@
     gtk_popover_set_pointing_to(GTK_POPOVER(m_popup), &windowRect);
     show();
 #else
-#if GTK_CHECK_VERSION(3, 24, 0)
+#if GTK_CHECK_VERSION(3, 24, 0) && PLATFORM(WAYLAND)
     GdkRectangle windowRect = { rect.x(), rect.y(), rect.width(), rect.height() };
     gtk_widget_translate_coordinates(m_webView, toplevel, windowRect.x, windowRect.y, &windowRect.x, &windowRect.y);
     gdk_window_move_to_rect(gtk_widget_get_window(m_popup), &windowRect, GDK_GRAVITY_SOUTH_WEST, GDK_GRAVITY_NORTH_WEST,