Related issue:
- https://github.com/uBlockOrigin/uBlock-issues/issues/1226
Related commit:
- 9eb455ab5e
In the previous commit, the element picker dialog was
isolated from the page content. This commit is to also
isolate the svg layers from the page content.
With this commit, there is no longer a need for an anonymous
iframe and the isolated world iframe is now directly
embedded in the page.
As a result, pages are now unable to interfere with any
of the element picker user interface. Pages can now only
see an iframe, but are unable to see the content of that
iframe. The styles applied to the iframe are from a user
stylesheet, so as to ensure pages can't override the
iframe's style properties set by uBO.
