Large number of stray live preview iframes in debugger

[abose]

• An iframe is added every time phoenix is reloaded. It could have something to do with panel reload.

See image below:

[abose]

Does not happen on Firefox with and without debugger open.

[abose]

• only happens when debugger is open in chrome. The iframes seems to be chrome debugger artifacts, they does not correspond to anything in the ui and seem to be empty.
• Cannot find any memory leaks as the issue is present even if we disable the live preview extension that creates the iframe, so this is most likely not our issue and some ui iss in chrome dev tools.
• Issue only happens if dev tools is open, if dev tools is not open and page reload is done many times, the stray iframes are not displlayed in dev tools after we open dev tools.

[abose]

Marking as wont fix as this is not our bug and most likeley a chrome debugger render issue.