**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
): void {
  
  for (var i = 0; i < updatePayload.length; i += 2) {
    var propKey = updatePayload[i];
    var propValue = updatePayload[i + 1];
    if (propKey === STYLE) {
      CSSPropertyOperations.setValueForStyles(domElement, propValue);
    } else if (propKey === DANGEROUSLY_SET_INNER_HTML) {
      setInnerHTML(domElement, propValue);
    } else if (propKey === CHILDREN) {
      setTextContent(domElement, propValue);
    } else if (isCustomComponentTag) {
      if (propValue != null) {
        DOMPropertyOperations.setValueForAttribute(
          domElement,
          propKey,
          propValue,
        );
      } else {
        DOMPropertyOperations.deleteValueForAttribute(domElement, propKey);
      }
    } else if (propValue != null) {
      DOMPropertyOperations.setValueForProperty(domElement, propKey, propValue);
    } else {
      
      
      
      DOMPropertyOperations.deleteValueForProperty(domElement, propKey);
    }
  }