**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
if (
    'selectionStart' in node &&
    ReactInputSelection.hasSelectionCapabilities(node)
  ) {
    return {
      start: node.selectionStart,
      end: node.selectionEnd,
    };
  } else {
    const win =
      (node.ownerDocument && node.ownerDocument.defaultView) || window;
    const selection = win.getSelection();
    return {
      anchorNode: selection.anchorNode,
      anchorOffset: selection.anchorOffset,
      focusNode: selection.focusNode,
      focusOffset: selection.focusOffset,
    };
  }
}
/**
 * Get document associated with the event target.
 *
 * @param {object} nativeEventTarget
 * @return {Document}
 */
function getEventTargetDocument(eventTarget) {