### 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
```
(e.g. when a fiber is re-rendered or when a fiber gets removed).
    displayNamesByRootID = new Map();
    initialTreeBaseDurationsMap = new Map(idToTreeBaseDurationMap);
    initialIDToRootMap = new Map(idToRootMap);
    idToContextsMap = new Map();
    hook.getFiberRoots(rendererID).forEach(root => {
      const rootID = getFiberID(getPrimaryFiber(root.current));
      ((displayNamesByRootID: any): DisplayNamesByRootID).set(
        rootID,
        getDisplayNameForRoot(root.current),
      );
      if (shouldRecordChangeDescriptions) {
         Rec
         Fib
         so 
        crawlToInitializeContextsMap(root.current);
      }
    });
    isProfiling = true;
    profilingStartTime = getCurrentTime();
    rootToCommitProfilingMetadataMap = new Map();
  }
  function stopProfiling() {
    isProfiling = false;
    recordChangeDescriptions = false;
  }
   Automatically start profiling so that we don't miss timing info from initial "mount".
  if (
    sessionStorageGetItem(SESSION_STORAGE_RELOAD_AND_PROFILE_KEY) === 'true'
  ) {