mozilla/addon-sdk — pull request #1418 by ZER0 (2014-03-04 22:40:05+00:00)
Title: Toolbar not customizable/966727

WIP, Unit Test is missing.

@gozala, I was trying to use the `customization` input we created in order to listen to the customization start / end once; but I wasn't able to make it working, I'm probably missing some crucial part:

```js
const customization = new CustomizationInput();
const { start, stop } = customization;

once(customization, "*", message => console.log(message));
start(customization);

// this is toggle the customization mode.
gCustomizeMode.toggle();
```

But only the `start` event is emitted, no `data`.