Computer Configuration > Administrative Templates > Google Chrome > Default search provider
Both
HKLM\Software\Policies\Google\Chrome
If DefaultSearchProviderEnabled is on, setting DefaultSearchProviderEncodings specifies the character encodings supported by the search provider. Encodings are code page names such as UTF-8, GB2312, and ISO-8859-1. They're tried in the order provided. Leaving DefaultSearchProviderEncodings unset puts UTF-8 in use. Example value: UTF-8 UTF-16 GB2312 ISO-8859-1