Git: Discard All Changes…
git.discardAll Throw away every local change: tracked files go back to the last commit and untracked files are deleted. Asks first.
How to run it
Open the command palette (M-x in the Emacs keymap) and search for Git: Discard All Changes…, then press Enter. It has no default keybinding, but you can bind one in Settings → Keymaps.