Chrome Version: 67.0.3381.0 (Official Build) dev (64-bit)
OS: OSX

What steps will reproduce the problem?
(1) Install sample extension Buildbot:
https://cs.chromium.org/chromium/src/chrome/common/extensions/docs/examples/extensions/buildbot/?type=cs&q=extensions/samples&sq=package:chromium
(2) Select details and then extension options
(3) view windowed options page ("options version 2")

What is the expected result?
Should like similar to:
https://cs.chromium.org/chromium/src/chrome/common/extensions/docs/static/images/options-ui.png?type=cs&sq=package:chromium

What happens instead?
Instead options page is small square with unnecessary scroll bar. Does not reflect updates to CSS in devtools. 

Additional Issues with live extension:
https://chrome.google.com/webstore/detail/chrome-extension-source-v/jifpbeccnghkjeaalbbjmodiffmgedin?hl=en

The windowed options page is displayed as long bar with no [X] to exit from window. Cannot click outside of window, must press [ESC].