The User Agent (UA) in Chrome for iOS is the same as the Mobile Safari
user agent, with CriOS/<ChromeRevision> instead of
Version/<VersionNum>.
Here’s an example of the Chrome UA on iPhone:
Mozilla/5.0 (iPhone; CPU iPhone OS 10_3 like Mac OS X)
AppleWebKit/602.1.50 (KHTML, like Gecko) CriOS/56.0.2924.75
Mobile/14E5239e Safari/602.1
For comparison, the Mobile Safari UA:
Mozilla/5.0 (iPhone; CPU iPhone OS 10_3 like Mac OS X)
AppleWebKit/603.1.23 (KHTML, like Gecko) Version/10.0
Mobile/14E5239e Safari/602.1
When the Request Desktop Site feature is enabled, the UA is the same as
Desktop Safari with CriOS/<ChromeMajorRevision> being added:
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_5)
AppleWebKit/605.1.15 (KHTML, like Gecko) CriOS/85
Version/11.1.1 Safari/605.1.15