### Describe what you were doing when the bug occurred:
1. I did profiling on a list, that gets updated on each pagination api call.
2. Once the profiling was done, I moved around in the Profiler to view the Flamegraph
3. Moving to second capture, the Profiler crashed.


**DevTools version**: 4.6.0-6cceaeb67

```
Component stack: in ec
    in div
    in div
    in div
    in So
    in Unknown
    in n
    in Unknown
    in div
    in div
    in rl
    in Ze
    in fn
    in Ga
    in _s
```
}
   We use this to simulate unmounting for Suspense trees
   when we switch from primary to fallback.
  function unmountFiberChildrenRecursively(fiber: Fiber) {
    if (__DEBUG__) {
      debug('unmountFiberChildrenRecursively()', fiber);
    }
     We might meet a nested Suspense on our way.
    const isTimedOutSuspense =
      fiber.tag === ReactTypeOfWork.SuspenseComponent &&
      fiber.memoizedState !== null;
    let child = fiber.child;
    if (isTimedOutSuspense) {
       If 
      const primaryChildFragment = fiber.child;
      const fallbackChildFragment = primaryChildFragment
        ? primaryChildFragment.sibling
        : null;
       Ski
      child = fallbackChildFragment ? fallbackChildFragment.child : null;
    }
    while (child !== null) {
       Rec
       We 
      if (child.return !== null) {
        unmountFiberChildrenRecursively(child);
        recordUnmount(child, true);
      }
      child = child.sibling;
    }