((Below is the QA Test Plan. I will upload the test extensions before merge day.))
- Open Firefox Beta 70 in a new profile
- Download the following test extensions attached to this bug:
- Test Extension 1: 1542035-test-extension-1-1.0.zip
- Extension with Background script and browserAction toolbar button. Clicking the browserAction toolbar button opens a popup with a menu.
- Test Extension 2: 1542035-test-extension-2-1.0.zip