MutationEvents and calculating new DIV size in WebKit?

Question

JavaScript

Faced the following problem in browsers of the WebKit family (Safari, Chrome, etc.)
When changing the content of a block, I need to recalculate its size. The specific task is customizing scroll bars in a widget inherited from ContentPane (Dojo), when changing the content size, it is necessary to recalculate the sizes of the sliders, etc. I implement it by catching the DOMSubtreeModified
event . Everything works in the Gecko family - it was tested on FF and SeaMonkey . Has anyone encountered a similar problem and how can it be solved?