title: Custom Wordpress image size not showing in 3.5 Media Manager
body: <p>I have a theme which uses add_image_size to define several custom image sizes. These 5 image sizes used to show up in the Wordpress 3.4 media manager when inserting an image into a post but they no longer show up in the new Wordpress 3.5 Media Manager.  In fact, the only image size options i get when I try to "Add Media" to a post are Thumbnail (100x100) and Full Size (3260x988).  Obviously my theme settings are not overriding the default media settings in Settings >> Media.  Here is the code from my functions.php file:</p>
  
  <pre><code>function custom_theme_support() {
    add_theme_support('post-thumbnails');
    set_post_thumbnail_size(180, 120, true);
    add_image_size( 'hero-desktop-2x', 3200, 800, true);
    add_image_size( 'hero-desktop', 1600, 400, true);
    add_image_size( 'hero-mobile-2x', 1534, 800, true);
    add_image_size( 'hero-mobile', 767, 400, true);
  }
  
  add_action('after_setup_theme','custom_theme_support');
  </code></pre>
  
  <p>So, my question is what do i need to do to make my theme override the Wordpress Admin settings in Wordpress 3.5?</p>