Now you can create a new search engine and even set it by default; however, the way to do this is only available on Windows according to Chrome Docs :
Overriding options is an extension method for overriding selected Chrome settings. The API is available only on Windows.
The bottom line is: if your list of web store extensions is associated with a verified domain used in the search , you can specify it in the manifest.
This means that you can only do this if you control the search engine page to the extent you confirm it for your account in Webmaster Tools .
Below is the minimum configuration:
"chrome_settings_overrides": { "name": "Example search", "keyword": "example", "search_url": "https://example.com/s?={searchTerms}", "favicon_url": "https://example.com/favicon.ico", "encoding": "UTF-8", "default": true },
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