This Chrome extension simulates Firefox's behavior on the hotkey Ctrl-W on a pinned tab; it does NOT close the tab.
You need to explicitly bind the key to ctrl+w in "Keyboard Shortcuts" in chrome://extensions/ to use the functionality (as in the screenshot above). This is not possible to do automatically.
The extension can't close DevTools windows correctly (due to safety limitations in the tabs API); see this issue. This will not be fixed.