![Screenshot 2019-12-16 10 51 05](https://user-images.githubusercontent.com/793565/70934095-fd91ed80-1ff1-11ea-93b5-746e816585ec.png)
There's seems to be circumstances where unmounted DOM/Fibers are kept alive by React DevTools. They're kept alive in `primaryFibers`:
https://github.com/facebook/react/blob/34527063083195558f98108cde10b5d6ad0d6865/packages/react-devtools-shared/src/backend/renderer.js#L772

It seems like a WeakSet would be appropriate and would remove the leak. Otherwise we'd need to understand why recordUnmount isn't called.

CC @bvaughn  
if (isMostRecentlyInspectedElement(id)) {
      const value = getInObject(
        ((mostRecentlyInspectedElement: any): InspectedElement),
        path,
      );
      const key = `$reactTemp${count}`;
      window[key] = value;
      console.log(key);
      console.log(value);
    }
  }
  function copyElementPath(id: number, path: Array<string | number>): void {
    if (isMostRecentlyInspectedElement(id)) {
      copyToClipboard(
        getInObject(
          ((mostRecentlyInspectedElement: any): InspectedElement),
          path,
        ),
      );
    }
  }
  function inspectElement(
    requestID: number,
    id: number,
    path: Array<string | number> | null,
  ): InspectedElementPayload {
    if (path !== null) {
      mergeInspectedPaths(path);
    }
    if (isMostRecentlyInspectedElement(id)) {