text: To simulate a more realistic user navigation, all supported navigation commands have been moved to the parent process (bug 1612831).
  We updated the checks for the current or top-level browsing context for all the commands to improve conformance with the WebDriver specification (bug 1493108).
  Fixed a bug in WebDriver:ElementClick that sometimes caused the command to return before the click event was actually synthesized (bug 1394354).
  The tabs.captureTab() and tabs.captureVisibleTab() methods now capture an area of the relevant tab's content specified by the rect property of the provided options object, or the visible area of the tab if this property is not provided (bug 1636508). Previously the rect property was not available, and these methods always captured the visible area of the relevant tab