Bug: Pinch-to-zoom on an iFrame can zoom past the app foreground

[nwittwer]

Problem
If you hover over an empty iframe and use pinch-to-zoom (trackpad for example), you will control the zoom level for the entire app.

This is challenging because there's iframes (which have their own with potentially different scale settings, it's really hard to prevent the whole app from zooming in when you pinch-to-zoom on top of iframes.

Expectation
Able to zoom inside of the iFrames, but it shouldn't change the zoom level of the whole window

Challenges

• Must be able to access all click/pointer events inside of the iFrame. So setting pointer-events:none won't work.
• Most websites will prevent injecting content into an iFrame