--HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Google\Update\AutoUpdateCheckPeriodMinutes to the REG_DWORD value of "0".

http://www.wikihow.com/Completely-Disable-Google-Chrome-Update
gpedit.msc

Local Computer Policy -> Computer Configuration -> Administrative Templates.  
Right-click on the entry, as seen in the screenshot above, 
and select “Add/Remove Templates…” and then browse to the location of 
the GoogleUpdate.adm template you downloaded just a moment ago.

Administrative Templates -> Classic Administrative Templates (ADM) -> Google 
-> Google Update -> Preferences -> Auto-update check period override