"Hold Cmd-Q to Quit" from Chrome
This is a change - Chrome thinks this is correct default behavior and shipped this enabled.


You can double press the Q - hold command and press and release Q twice as quickly as you are comfortable - ⌘ Q Q
Or change the default to match your expectations and all other programs - see below to change the default setting


Select Chrome in the menu bar and select to un-check Warn before Quitting (⌘Q) 



This can also be found in Chrome's Preferences (Cmd,), in the Appearance section: