Uncaught SyntaxError: Failed to construct 'Intersection': rootMargin must be specified in pixels or percent.

[ghost]

Not sure if this is a coding problem with Google Canary 52, but this error comes up in both your examples because of this:

{ rootMargin: "200% 0" }

If you add a percentage with the 0 so it becomes:

{ rootMargin: "200% 0%" }

The error goes away!

Noticed this error in Delay Loading Example.