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

): HostContext {
    if (__DEV__) {
      const parentHostContextDev = ((parentHostContext: any): HostContextDev);
      const namespace = getChildNamespace(parentHostContextDev.namespace, type);
      const ancestorInfo = updatedAncestorInfo(
        parentHostContextDev.ancestorInfo,
        type,
        null,
      );
      return {namespace, ancestorInfo};
    }
    const parentNamespace = ((parentHostContext: any): HostContextProd);
    return getChildNamespace(parentNamespace, type);
  },
  getPublicInstance(instance) {
    return instance;
  },
  prepareForCommit(): void {
    eventsEnabled = ReactBrowserEventEmitter.isEnabled();
    selectionInformation = ReactInputSelection.getSelectionInformation();
    ReactBrowserEventEmitter.setEnabled(false);
  },
  resetAfterCommit(): void {
    ReactInputSelection.restoreSelection(selectionInformation);
    selectionInformation = null;
    ReactBrowserEventEmitter.setEnabled(eventsEnabled);
    eventsEnabled = null;
  },
  createInstance(
    type: string,