**Do you want to request a *feature* or report a *bug*?**
*Feature*

**What is the current behavior?**
In Firefox the `dialog` element is not implemented. We use a polyfill to be able to support it. Everything works well. But React warns that the `dialog` element is unrecognized, and this on each page load, which is quite useless (for this specific case).
I would like the possibility to disable the  warning but only for some elements. So the utility of this warning remains when the developer mistype the component name.

**What is the expected behavior?**
Once we specified which tag are "accepted/normal" React will not warn on specified unrecognized tags.

**Which versions of React, and which browser / OS are affected by this issue? Did this work in previous versions of React?**
React 16
Firefox 57

In previous versions there was no warning.

Is this clear enough? Do you need any other information?
Cheers
} else if (propKey === CHILDREN) {
      if (typeof nextProp === 'string') {
        setTextContent(domElement, nextProp);
      } else if (typeof nextProp === 'number') {
        setTextContent(domElement, '' + nextProp);
      }
    } else if (propKey === SUPPRESS_CONTENT_EDITABLE_WARNING) {
      
    } else if (registrationNameModules.hasOwnProperty(propKey)) {
      if (nextProp != null) {
        if (__DEV__ && typeof nextProp !== 'function') {
          warnForInvalidEventListener(propKey, nextProp);
        }
        ensureListeningTo(rootContainerElement, propKey);
      }
    } else if (isCustomComponentTag) {
      DOMPropertyOperations.setValueForAttribute(domElement, propKey, nextProp);
    } else if (nextProp != null) {
      
      
      
      DOMPropertyOperations.setValueForProperty(domElement, propKey, nextProp);
    }
  }
}
function updateDOMProperties(
  domElement: Element,
  updatePayload: Array<any>,
  wasCustomComponentTag: boolean,
  isCustomComponentTag: boolean,