CloudMade/Leaflet — pull request #746 by danzel (2012-06-22 04:47:28+00:00)
Title: Performance improvements for TileLayer (Mainly with reuseTiles)

When using layer.options.reuseTiles img elements are moved around in the DOM rather than removing them and re-adding them which improves performance. (google maps uses this trick too).
class += ' leaflet-tile-loaded' would get ran multiple times when using reuseTiles, this doesn't happen any more.

Tiles within a layer are positioned using top/left rather than a 3d transform. This gives better general performance in chrome due to less GPU compositing (see second commit message).

These performance improvements affect desktop browsers (where reuseTiles is off by default) more than mobile as the mobile pan animation stops tile loading while it is running.