Computer Configuration > Administrative Templates > Google Chrome > Content settings
Both
HKLM\Software\Policies\Google\Chrome
Setting the policy to 1 lets sites track the users' physical location as the default state. Setting the policy to 2 denies this tracking by default. You can set the policy to ask whenever a site wants to track the users' physical location. Leaving the policy unset means the AskGeolocation policy applies, but users can change this setting.