Due to Chrome bug ( http://crbug.com/319328 ), when "block third party cookies" setting is enabled CSS-Diff is not fully functional:
- comparing elements from different tabs won't work
- closing DevTools clears CSS-Diffs' history
I can't fix it, we need to wait for the Chromium team to do so.
For these who are wondering why I haven't used chrome.storage: http://crbug.com/178618 .