When inspecting an element with a style applied from an `adoptedStyleSheet`, the inspector displays the style as originating from a locked `User Agent Style Sheet`. This makes it impossible to use the inspector to alter the style or know from where it's originating. See https://jsbin.com/juhucaw/2/edit?html,output. Steps to reproduce: 1. Inspect the blue div 2. Look at it's styles. Expected: 1. styles are editable in the inspector 2. styles are reported as coming from an adoptedStyleSheet Actual: 1. styles are locked in the inspector 2. styles are reporeted as coming from `User Agent Style Sheet`.