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

**What is the current behavior?**
After an `onDrop` event has fired inside an "editable" element (input, textarea, contentEditable), the `onSelect` event on that element will no longer fire when changing selection using the keyboard. 

As you can see in this gif below, the onSelect event gets called each time I move the cursor around (using the arrow keys). But once the `onDrop` event has fired, `onSelect` will no longer fire when I move the cursor around (also using the keys):

![react-onselect-bug](https://user-images.githubusercontent.com/3599069/32080216-bd42f580-baae-11e7-98ee-93a482ed80ca.gif)

[Here's the jsfiddle](https://jsfiddle.net/owmL8n6u/1/) I used to record the video above.

**What is the expected behavior?**
The `onSelect` event should always fire when selection changes.

**Which versions of React, and which browser / OS are affected by this issue? Did this work in previous versions of React?**
React 16 / Chrome 62
const doc = getEventTargetDocument(nativeEventTarget);
  if (
    mouseDown ||
    activeElement == null ||
    activeElement !== getActiveElement(doc)
  ) {
    return null;
  }
  
  const currentSelection = getSelection(activeElement);
  if (!lastSelection || !shallowEqual(lastSelection, currentSelection)) {
    lastSelection = currentSelection;
    const syntheticEvent = SyntheticEvent.getPooled(