Keyboard Shortcut Keys for Chrome Hangout App

Keyboard shortcut keys helps users to done certain task easily and quickly without touching the mouse. Are you using Google's Hangout messaging app to your computer? Here I listed some useful shortcut keys to done specific commands on your hangout app

Ctrl + B
 Cmd + B
Ctrl + I
Cmd + I
Ctrl + U
Cmd + U
Refresh Hangouts List 
Ctrl + R
Cmd + R
Close Hangouts List
Ctrl + W
Cmd + W

Common Short Keys for all computers:

Close Hangout Window: Click on specific Hangout Window and press Esc

Minimize all hangouts window at once
:  Press Shift and click the minimize button in one window (It works only on Hangout Chrome Extension.
Note: Above shortcut keys are perfectly works on Windows 7 ultimate computers (I checked many times). But I didn't checked on other computers. So please mention in comments if you find any bug and new shortcut keys.