Yes, that was Chrome. As I said, it does this in addition to Flash Player's request for access to the mic. So for somebody who hasn't used it on a given site (in Chrome) before, the process (assuming the user accepts everything) is as follows:
- When the page loads, the recorder will display the Flash Player settings request for access to the microphone
- User allows access
- User clicks play button
- Recorder starts recording silence
- Chrome slides out the banner in the screenshot above
- User clicks on "Allow"
- Recorder starts actually receiving audio
So it seems that Chrome has tried to be clever by supplying Flash Player with a silent audio source until the user grants access (again). This is quite annoying, since Flash Player already allows the user to control access; my guess is that it's an attempt at consistency with the HTML5 getUserMedia() system, which uses the same grey banner at the top of the page - and I think it's even consolidated, so granting Flash Player access will then allow getUserMedia() the same access from that site (and vice versa, assuming Flash is also granted access through its own system). To me, this seems like a half-baked attempt - if Chrome wants to control Flash Player's access to mic/webcam, it should take over completely rather than adding a second layer of settings; that's a pretty big step, though, since it'd require changes to Flash Player and would make the behaviour inconsistent between different Flash Players (Chrome's Pepper Flash vs everyone else's Flash). This isn't really the place for that discussion, so I'll hunt for existing discussions in the appropriate places (and start one if there isn't already one).