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

**What is the current behavior?**
If there is a client/server mismatch for text inside of an a or button element, it causes it to be automatically focused on page load.

**If the current behavior is a bug, please provide the steps to reproduce and if possible a minimal demo of the problem via https://jsfiddle.net or similar (template for React 16: https://jsfiddle.net/Luktwrdm/, template for React 15: https://jsfiddle.net/hmbg7e9w/).**
```
let text;
let URL = '/randomURL';
if (typeof window !== 'undefined') {
  text = 'CLIENT TEXT';
} else {
  text = 'TEXT';
}

return (
  <a href={URL}>
    {text}
  </a>
);
```

if the focus is not on the window (i.e. if a dom element is selected in the chrome inspector or react inspector widnow), then it doesn't add the focus.

**What is the expected behavior?**
The expected behavior is that it would either show CLIENT TEXT or TEXT (depending on how React16 resolves the diff), but for it not to be automatically highlighted 

**Which versions of React, and which browser / OS are affected by this issue? Did this work in previous versions of React?**
React16 / macosx / chrome + ff + safari
): void {
      if (container.nodeType === COMMENT_NODE) {
        (container.parentNode: any).insertBefore(child, beforeChild);
      } else {
        container.insertBefore(child, beforeChild);
      }
    },
    removeChild(
      parentInstance: Instance,
      child: Instance | TextInstance,
    ): void {
      parentInstance.removeChild(child);
    },
    removeChildFromContainer(
      container: Container,
      child: Instance | TextInstance,
    ): void {
      if (container.nodeType === COMMENT_NODE) {
        (container.parentNode: any).removeChild(child);
      } else {
        container.removeChild(child);
      }
    },
  },
  hydration: {
    canHydrateInstance(
      instance: Instance | TextInstance,
      type: string,
      props: Props,
    ): null | Instance {