Remove injectReactDOMEventListener from ReactBrowserEventEmitter (#9656)

* Remove injectReactDOMEventListener from ReactBrowserEventEmitter

This PR removes the injection of ReactDOMEventListener from
ReactBrowserEventEmitter. Instead, the required initialization will
happen directly in ReactDOMInjection.

This injection was (probably) originally implemented for React Native
but never used, so we can clean it up.

* Mention how to see the full ouput of fiber tests

contributing/how-to-contribute.md

@@ -83,7 +83,7 @@ The core team is monitoring for pull requests. We will review your pull request
 5. Make sure your code lints (`npm run lint`).
 6. Format your code with [prettier](https://github.com/prettier/prettier) (`npm run prettier`).
 7. Run the [Flow](https://flowtype.org/) typechecks (`npm run flow`).
-8. If you added or removed any tests, run `./scripts/fiber/record-tests` before submitting the pull request, and commit the resulting changes.
+8. If you added or removed any tests, run `./scripts/fiber/record-tests` before submitting the pull request, and commit the resulting changes. You can see the full output of fiber tests with `REACT_DOM_JEST_USE_FIBER=1 npm test`.
 9. If you haven't already, complete the CLA.
 
 ### Contributor License Agreement (CLA)