It appears there has been a regression in the current version of Chrome for OS X (Version 46) which causes graphical distortion when Chrome windows are in use on USB-attached monitors.
Until this issue is fixed in a future version of Chrome, the best current workaround is to disable hardware acceleration in Chrome. To do so:
Click the Chrome menu header -> Preferences -> Settings -> Show advanced settings -> Scroll down to “System” -> Uncheck “Use hardware acceleration when available”.
To help make Google aware of the issue so they can properly prioritize fixing the issue, affected users can report the regression to Google using the built-in bug reporter: Preferences -> About -> Report an issue