[jerdog]

With the link that @itake posted above, you can definitely use CircleCI to do the deploy automatically. Now if you're concerned about missing something in QA, you could add an approval step (https://circleci.com/docs/workflows#holding-a-workflow-for-a...) in your CircleCI pipeline so that the browser extension is deployed locally for testing, and once it's been tested you can have the next steps approved where it deploys to Production (Google). This concern is really the same for anyone, regardless of if you use CircleCI or not.

DISCLAIMER: I work for CircleCI