This test is intended to verify Break On Mutate support within the
HTML panel. This features allows to debug mutation events (DOMAttrModified,
DOMCharacterDataModified, DOMNodeInserted, DOMNodeRemoved)
Open Firebug and select the HTML panel.
Expand body element
Right-click on the content element (it's the green h3 'Test Element')
Step by step pick:
Break on Attribute Change
Break on Child Addition or Removal
Break on Element Removal
Use button below to fire appropriate changes and check that Firebug
always breaks at the proper location.
Test Element
Make sure extensions.firebug.filterSystemURLs preference is set to true.
If not, set it and reload the page.