'View Repository' button with Chrome(ium) extension disappearing.

Created by: cedws

• Sourcegraph version: N/A (Extension 19.1.29.2106)
• Platform information: Chromium 71.0.3578.98

Steps to reproduce:

1. Install the Sourcegraph extension

2. Navigate around various pages on GitHub

3. Observe that the View Repository button usually next to Watch is missing

4. Refresh the page

5. Observe that the View Repository button is now visible

6. Continue to navigate around GitHub

7. Observe that the View Repository button disappears again

Expected behavior:

The View Repository button should remain visible and not only be visible after a page refresh.

Actual behavior:

The View Repository button disappears unless the page is refreshed, but later disappears again after continuing to browse GitHub.