File → Close Window (⇧⌘W).
⌘W closes the tab which will close the window if this is the last tab, but ⇧⌘W closes the window containing any number of tabs.
This menu and shortcut is standard macOS working in all tabbed apps implementing macOS tabs, and Google Chrome has applied this shortcut to their tab implementation.
You can easily delete all the bookmarks in Google Chrome in one go.
Open Bookmark manager by going to Bookmarks → Bookmark Manager or by using keyboard short Option + Command + B.
Use the keyboard shortcut Command + A to select all bookmarks and folders.
Press the Delete key to delete all the bookmarks in one go.
Do note that Google Chrome doesn't ask for ...
Found a great way on Chrome Version 75.0.3770.100:
1) go to the website you want to convert to an app
2) click on three dots / more tools / Create Shortcut + make sure to tick 'open in new window'
That's it - you now have an app that you can pin to your dock and you can cycle through them with cmd + tab. Awesome!