**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
type Props = {
  autoFocus?: boolean,
  children?: mixed,
  hidden?: boolean,
  suppressHydrationWarning?: boolean,
};
type Instance = Element;
type TextInstance = Text;
type HostContextDev = {
  namespace: string,
  ancestorInfo: mixed,
};
type HostContextProd = string;
type HostContext = HostContextDev | HostContextProd;
let eventsEnabled: ?boolean = null;
let selectionInformation: ?mixed = null;
type Batch = FiberRootBatch & {
  render(children: ReactNodeList): Work,
  then(onComplete: () => mixed): void,
  commit(): void,
  
  
  
  _root: Root,
  _hasChildren: boolean,
  _children: ReactNodeList,
  _callbacks: Array<() => mixed> | null,
  _didComplete: boolean,
};
function ReactBatch(root: ReactRoot) {