Environment Details:
Application Name: Visual Studio Code
Application Version: 1.38.1 (user setup)
Commit: b37e54
Electron: 4.2.10
Node.js: 10.11.0
OS: Windows_NT x64 10.0.18362

Repro steps:

1. Go to Extensions
2. Pick any ol' extension (confirmed on Java Extension Pack)
3. Use keyboard to select "Install" button
4. Hit on keyboard

Expectation:
Keyboard focus is moved to the resulting toast, allowing me to dismiss or take action.

Reality:
Keyboard focus stays in the main editor window, where it was before. Difficult or impossible to tab to the resulting toast.