`injectComponentClasses` won't work for ReactHostComponent

[snowmantw]

I try to extend my own renderer and found the code in React codebase:

https://github.com/facebook/react/blob/20bcabb1ea4cf492ade240bd6915b4bd44f04895/src/renderers/shared/stack/reconciler/ReactHostComponent.js#L18

actually won't use costumed registry for component mapping.

Such implementation has been changed: now they use the generic component to dispatch to the correct one. The latest commit and file still uses the pattern is:

https://github.com/facebook/react/pull/4030/files#diff-2d144b75481a75f394d00eedc6005297L112

In the current version, it has become things like this:

https://github.com/facebook/react/blob/30aa84181d98dc9498f7e1eb3ded817d8faf65f6/src/renderers/dom/shared/ReactDOMComponent.js#L537

Concluded by that, I changed my implementation to dispatch to the corresponding constructor via the generic one. So maybe the comment should be changed as well.