If the custom background default wp-head-callback (_custom_background_cb) is used, we use postMessage for all custom background properties. Otherwise, we use full refreshes.
When using postMessage, the preview recalculates the custom background CSS block, allowing it to omit CSS values when they are not present and fall back on the original CSS.
git-svn-id: http://core.svn.wordpress.org/trunk@20908 1a063a9b-81f0-0310-95a4-ce76da25c4cd
* Rename WP_Customize to WP_Customize_Manager.
* Move customize-controls.php to wp-admin/customize.php.
* Make customize.php the formal entry point, rather than admin.php?customize=on.
* Rename is_current_theme_active() to is_theme_active().
* Add getters for the theme, settings, controls, and sections properties.
* Allow customize.php (no ?theme=) to load the active theme. Not used yet.
see #20736.
git-svn-id: http://core.svn.wordpress.org/trunk@20852 1a063a9b-81f0-0310-95a4-ce76da25c4cd
koopersmith
nacin