There are some similarities to the 32 bit x86 NaCL and one of the early NaCl paper mentions this. https://storage.googleapis.com/pub-tools-public-publication-...

They both use x86 memory segment functionality for limiting memory access, but seems like there are also plenty of things they do differently. And the x86_64 and ARM versions of NaCl are even more different, they can't use the segment registers so they use masking instead.

Doesn't look like it: https://www.chromium.org/nativeclient/reference/external-res...