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

const hostContextDev = ((hostContext: any): HostContextDev);
      if (
        typeof newProps.children !== typeof oldProps.children &&
        (typeof newProps.children === 'string' ||
          typeof newProps.children === 'number')
      ) {
        const string = '' + newProps.children;
        const ownAncestorInfo = updatedAncestorInfo(
          hostContextDev.ancestorInfo,
          type,
          null,
        );
        validateDOMNesting(null, string, null, ownAncestorInfo);
      }
    }
    return diffProperties(
      domElement,
      type,
      oldProps,
      newProps,