Accessibility extension slowing down other extensions that use iframes

[randalpinto]

We're building a chrome extension where the content script creates an iframe inside of the host webpage and loads a .html file that is packaged with the extension inside of this iframe. The .html in turn has another iframe that loads content from our web server.

These iframes get created and removed based on user interaction.

Whenever the accessibility developer tools extension is also loaded on the browser, every time that our extension creates one of these iframes the time to load the iframe get progressively longer and at some point freezes the whole page. Everything works fine without the Accessibility Extension.

We've noticed two things that might help with investigation:

1. Our iframe receives a number of postMessages with data.request = 'getUri' every time it gets loaded
2. Eventually the Accessibility Extension starts throwing thousands of the following errors: "Cannot read property 'frameURIs' of undefined"