Legacy Theme Preview Removed in 4.3

This release we removed the old code for the Legacy Theme Preview, which hasn’t been maintained since the introduction of the customizer in WordPress 3.5. Recently, we noticed that the theme preview no longer works when using a static front page. We kept the old theme preview for no-JS and some browsers that were less capable. But since browsers are doing a better job today we don’t need to continue fixing/shipping this legacy code. It’s removed in [33492].

#4-3, #dev-notes, #themes