UserAgent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/66.0.3359.117 Safari/537.36

Steps to reproduce the problem:
1. Open http://pdftron.s3.amazonaws.com/downloads/webviewer/test/samples/basic/index.html?doctype=pdf
2. Use the dropdown at the top to switch between different documents and confirm that they load.
3. Press the Toggle Visibility button to hide the viewer. Then press it again to show it. This just adds/removes display: none on the viewer element.
4. Use the dropdown to switch to another document and the message "NativeClient: NaCl module crashed" appears in the console.

What is the expected behavior?
The native client doesn't crash and documents can continue to be loaded.

What went wrong?
It seems like this is a change behavior from Chrome 64. I installed Chrome 64 and confirmed that this does not happen, but starting in Chrome 65 it does happen. Also note that adding visibility: hidden instead of display: none does not trigger the crash.

Did this work before? Yes Chrome 64

Does this work in other browsers? Yes

Chrome version: 66.0.3359.117  Channel: stable
OS Version: 10.0
Flash Version: