Extension API: chrome.tabs.onActivated

[jonathansampson]

https://developer.chrome.com/extensions/tabs#event-onActivated

• chrome.tabs.onActivated.addListener(listener)
• chrome.tabs.onActivated.removeListener(listener)
• chrome.tabs.onActivated.hasListener(listener)

As of 4e86cab, Brave supports onActivated.addListener, but not hasListener or removeListener. Attempting to call the latter 2 methods will results in a TypeError.

Blocks #6366, #9330, #9531

[jonathansampson]

Although the addListener method is supported, the API is presently a noop.