When debugging it is sometimes interesting to understand what script triggers a change in the DOM of the document. A contextual menu providing the possibility of breaking * on modifying the content of an element such as innerHTML * on modifying a specific attribute value * on initiating a specific download Similar feature in chrome. https://cloudup.com/cgysCC63-dy

I suspect this is a duplicate of bug 1005825 ( even though it is in a different component ). In particular, exiting tools expose this feature in the inspector, so that's probably where the bug should live.