This is a bug report.

**Expected Behavior**
React should not suggest me to download the DevTools extension in a `chrome-extension://` page, because the extension has no permission to inject the devtool.

**Actual Behavior**
`Download the React DevTools and use an HTTP server (instead of a file: URL) for a better development experience: https://fb.me/react-devtools`

**Reproducing**

1. Create a Chrome extension with an `option` or `popup` page that uses React
2. Load the extension to Chrome and open up that page.
3. Observe console.

**Version**
Google Chrome 56.0.2924.3
React 15.4.0

DOMRenderer.unbatchedUpdates(() => {
        renderSubtreeIntoContainer(null, null, container, false, () => {
          container._reactRootContainer = null;
        });
      });
      
      
      return true;
    } else {
      if (__DEV__) {
        const rootEl = getReactRootElementInContainer(container);
        const hasNonRootReactChild = !!(rootEl &&
          ReactDOMComponentTree.getInstanceFromNode(rootEl));
        
        const isContainerReactRoot =
          container.nodeType === 1 &&
          isValidContainer(container.parentNode) &&
          !!container.parentNode._reactRootContainer;
        warning(
          !hasNonRootReactChild,
          "unmountComponentAtNode(): The node you're attempting to unmount " +
            'was rendered by React and is not a top-level container. %s',
          isContainerReactRoot
            ? 'You may have accidentally passed in a React root node instead ' +
                'of its container.'
            : 'Instead, have the parent component update its state and ' +
                'rerender in order to remove this component.',
        );
      }
      return false;