[From the Profiler docs](https://reactjs.org/docs/profiler.html#onrender-callback):

> The Profiler requires an onRender function as a prop. React calls this function any time a component within the profiled tree “commits” an update.

However, given:

```jsx
import React from 'react'
import ReactDOM from 'react-dom'

function Counter() {
  const [count, setCount] = React.useState(0)
  const increment = () => setCount(c => c + 1)
  return <button onClick={increment}>{count}</button>
}

function App() {
  return (
    <div>
      <React.Profiler
        id="counter"
        onRender={() => console.log('called')}
      >
        <div>
          Profiled counter
          <Counter />
        </div>
      </React.Profiler>
      <div>
        Unprofiled counter
        <Counter />
      </div>
    </div>
  )
}

ReactDOM.render(<App />, document.getElementById('root'))
```

I'm getting a log when I click on the unprofiled counter.

Reproduction: https://codesandbox.io/s/react-codesandbox-tnff6

Am I misunderstanding this API, or is this a bug?
'A context consumer was rendered with multiple children, or a child ' +
        "that isn't a function. A context consumer expects a single child " +
        'that is a function. If you did pass a function, make sure there ' +
        'is no trailing or leading whitespace around it.',
    );
  }
  prepareToReadContext(workInProgress, renderExpirationTime);
  const newValue = readContext(context, newProps.unstable_observedBits);
  let newChildren;
  if (__DEV__) {
    ReactCurrentOwner.current = workInProgress;
    setCurrentPhase('render');
    newChildren = render(newValue);
    setCurrentPhase(null);
  } else {
    newChildren = render(newValue);
  }
  
  workInProgress.effectTag |= PerformedWork;
  reconcileChildren(current, workInProgress, newChildren, renderExpirationTime);
  return workInProgress.child;
}
function updateFundamentalComponent(
  current,
  workInProgress,
  renderExpirationTime,
) {
  const fundamentalImpl = workInProgress.type.impl;
  if (fundamentalImpl.reconcileChildren === false) {
    return null;