Chrome Version: 57.0.2930.0
OS: Chrome OS

What steps will reproduce the problem?
(1) Visit a page with an embedded PDF (e.g. http://plugindoc.mozdev.org/testpages/pdf.html)
(2) Pinch zoom in on the area outside of the PDF viewer

What is the expected result?
The page scale factor should be applied correctly on the PDF viewer.

What happens instead?
The page scale factor is not applied correctly. In particular the content is not rastered properly and the viewer's controls are scaled out of view.