hey folks, looks like [this code](https://github.com/facebook/react/commit/b565f495319750d98628425d120312997bee410b) added small issue with safari and it could flood devtools console output with messages like this:
<img width="875" alt="screenshot 2018-10-26 at 15 25 33" src="https://user-images.githubusercontent.com/778908/47569863-0e3a5c80-d935-11e8-8e59-8d95d35ba131.png"> 
As I understand it happens [here](https://github.com/facebook/react/commit/b565f495319750d98628425d120312997bee410b#diff-a654f37b01573fc8006b426d56ad53ceR50) and I see you catch the error, but safari still adds the error message if you have iframes with different origin
const curFocusedElem = getActiveElementDeep();
  const priorFocusedElem = priorSelectionInformation.focusedElem;
  const priorSelectionRange = priorSelectionInformation.selectionRange;
  if (curFocusedElem !== priorFocusedElem && isInDocument(priorFocusedElem)) {
    if (
      priorSelectionRange !== null &&
      hasSelectionCapabilities(priorFocusedElem)
    ) {
      setSelection(priorFocusedElem, priorSelectionRange);
    }
    
    const ancestors = [];
    let ancestor = priorFocusedElem;
    while ((ancestor = ancestor.parentNode)) {
      if (ancestor.nodeType === ELEMENT_NODE) {
        ancestors.push({
          element: ancestor,
          left: ancestor.scrollLeft,
          top: ancestor.scrollTop,
        });
      }
    }
    if (typeof priorFocusedElem.focus === 'function') {
      priorFocusedElem.focus();
    }
    for (let i = 0; i < ancestors.length; i++) {
      const info = ancestors[i];
      info.element.scrollLeft = info.left;
      info.element.scrollTop = info.top;