Reorder tabs with cmd+shift+p and cmd+shift+\.
This extension adds two hotkeys:
cmd + shift + P (move current tab left: wraps if at index/position 0)
cmd + shift + O (move current tab right: wraps if at index/position len(tabcount))
Why '\\' was not used:
If your keys are already bound (shouldn't be by default), you will need to re-bind them in your chrome extensions options page (scroll to the bottom)