UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.99 Safari/537.36

Steps to reproduce the problem:
So, we actually ran into this trying to put an iframe in a chrome extension and finding out that for whatever reason pinch to zoom stopped working, but upon further investigation it became clear that it wasn't just a chrome extension issue, but rather ANY iframe on a different origin never receives pinch events (i.e. scrollwheel event with ctrlKey set to true). The host page (expectedly) also doesn't receive it, so the event is just lost.

I've provided a reduction that can be run in 3 different modes:

1. You can drag and drop xorigin-punch-reduction/index.html into your browser to test it from the file:// origin.
2. You can start up a simple server (ala python -m SimpleHTTPServer 9090) and view it by doing localhost://9090 (if you use a different port, please do localhost://PORT?port=PORT, sorry this isn't more ideal)
3. You can install it as an extension (but you will still have to run the server for one of the 4 test cases included).

Once loaded, you will see something like the attached image. There are four quadrants on the page:

1. TOP LEFT: This will ALWAYS work in every of the above configuration, it just reports pinch events on the host index.html page.
2. BOTTOM LEFT: This will ALWAYS work in every of the above configurations as well, as it loads a test page in an iframe with a relative URL. Thus, when loaded locally it uses file://, when loaded on localhost it uses localhost, and when loaded on chrome-extension:// it will use chrome-extension://.

3. TOP RIGHT: This will NEVER work in every of the above configurations. Since it is a google maps iframe and none of the configurations are on the google.com origin, the map will never receive pinch events. Interestingly enough, this means the only please pinch to zoom works on google maps is the google maps developer page, which is in retrospect hilariously frustrating, as initially we kept thinking we were just doing something wrong as we kept checking back to that page.
4. BOTTOM RIGHT: This will ONLY work in the localhost configuration. This is because the page loads "localhost:9090/iframe.html", so in file:// and chrome-extension:// it fails due to cross origin (I guess?), but in localhost it passes same origin.

What is the expected behavior?
I expect pinch to zoom to work in all 4 configurations, scrollwheel with ctrlKey true seems to be the only kind of event that is just completely swallowed in this scenario. It is completely understandable that the host page does not receive the event (as that would match the behavior will other events), but I don't understand why the iframe doesn't receive it.

What went wrong?
Scrollwheel event wasn't sent.

Did this work before? N/A 

Does this work in other browsers? N/A

Chrome version: 67.0.3396.99  Channel: stable
OS Version: OS X 10.13.5
Flash Version:
 

Deleted: example.png 439 KB

	example.png 439 KB View Download

Deleted: xorigin-scrollwheel-reduction.zip 10.6 KB

xorigin-scrollwheel-reduction.zip 10.6 KB Download