### 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
```
pushOperation(hasOwnerMetadata ? 1 : 0);
      if (isProfiling) {
        if (displayNamesByRootID !== null) {
          displayNamesByRootID.set(id, getDisplayNameForRoot(fiber));
        }
      }
    } else {
      const {key} = fiber;
      const displayName = getDisplayNameForFiber(fiber);
      const elementType = getElementTypeForFiber(fiber);
      const {_debugOwner} = fiber;
      const ownerID =
        _debugOwner != null ? getFiberID(getPrimaryFiber(_debugOwner)) : 0;
      const parentID = parentFiber
        ? getFiberID(getPrimaryFiber(parentFiber))
        : 0;
      const displayNameStringID = getStringID(displayName);
       Thi
       in 
      const keyString = key === null ? null : '' + key;
      const keyStringID = getStringID(keyString);
      pushOperation(TREE_OPERATION_ADD);
      pushOperation(id);
      pushOperation(elementType);
      pushOperation(parentID);
      pushOperation(ownerID);
      pushOperation(displayNameStringID);
      pushOperation(keyStringID);
    }
    if (isProfilingSupported) {