Short answer: yes, since you are using Windows it probably uses the OS.
Longer answer: it depends on a number of factors. First of all if you are using the option for 'enhanced spell check' in Chrome, which uses the a web-service from Google. It also depends on the OS and on the language you've selected.
Chromium documentation states that:
On Windows, the platform spell checker relies on user-installed language packs. It is possible for a user to enable spell checking in Chrome for a language while not having installed the necessary language pack in the Windows settings.
For those situations, the spell checker on Windows will first try to use the platform spell checker. For languages where this is not possible, Hunspell will be used instead.
Source
This can be seen in Chrome itself too, by checking the flags:
chrome://flags/#win-use-native-spellchecker
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